Breast Biopsy Research Articles

Abstract PO1-28-06: Development of a plasma-based real-time qPCR gene expression assay for targeted screening and diagnosis of early-stage breast cancer

Abstract Background Over 12 million US women undergo follow-up breast imaging and exams annually due to breast cancer suspicions, incurring an $8 billion total cost, of which $2.18 billion is attributed to false-positive breast biopsies. Recent updates published to the Mammography Quality Standards Act (MQSA) now recommend supplemental imaging for women with heterogeneously dense and extremely dense breasts, regardless of suspicious findings. Given sensitivity limitations associated with mammography in dense-breasted women, as low as 30-47%, and non-specificity associated with ultrasound and MRI, these recent recommendations are likely to further strain the healthcare system and place substantial burden on patients and providers. With an estimated 25 million dense-breasted women who regularly screen for breast cancer now considered at-risk, there is a critical need for affordable and highly accurate testing, offering better specificity without sacrificing sensitivity. To address this gap, we developed an affordable and accurate plasma-based gene expression assay using real-time qPCR for targeted screening and diagnosis of early-stage breast cancer. Methods In previous studies, 26 cross-correlated mRNA gene targets were discovered and independently validated for non-invasive breast cancer detection across five independent patient cohorts using microarray gene expression profiling, comprised of peripheral blood mononuclear cells (n=337) and saliva (n=20), demonstrating strong efficacy, reproducibility, and concordance across bio-fluids and assay platforms in all studies. A sixth independent validation cohort comprised of 203 plasma samples was subsequently obtained for real-time qPCR clinical assay development and validation in our CLIA laboratory. The CLIA validation cohort was designed to be representative of different diagnosis status, stage, and ethnicity, and included Caucasian, Black/African American, Hispanic, and Asian women. After normalizing mRNA expression and clustering analysis, the signature was refined to 8 target genes and was assessed in a cohort of 87 plasma samples [Table 1] to verify the assay’s diagnostic performance for stage I breast cancer detection, under locked laboratory protocols. We leveraged machine learning methods derived from XGBoost classification, a supervised-learning algorithm that uses sequentially built shallow decision trees to provide accurate results and avoidance of overfitting. Results The XGBoost model, selecting from the 8 mRNA gene targets and patient age, achieved >99% sensitivity, 89% specificity for stage I breast cancer detection in the held-out test set, with an overall diagnostic accuracy of 94.5%. Normalized data showed significant differences in gene expression between healthy controls and stage I patients, and distinct clustering was observed for the 8 mRNA gene signature, including patient age. Conclusions Our plasma-based real-time qPCR gene expression clinical assay, with machine learning, is positioned as a highly accurate non-invasive tool for targeted screening and diagnosis of early-stage breast cancer. Furthermore, a clinically validated assay in this space addresses the need for more targeted diagnostics, while serving as a promising tool for clinicians as they make critical care decisions across the breast health continuum, accelerating time to earlier and more precise intervention and treatment, mitigating unnecessary healthcare expenditures, and reducing the mental, emotional, and financial burden on patients and their families. Citation Format: Martin Keiser, Elizabeth Cormier-May, Matthew Alderdice, Joy Kavanagh, William Guesdon, Heather Healy, Nathalie Jean-Charles, Jay Harness. Development of a plasma-based real-time qPCR gene expression assay for targeted screening and diagnosis of early-stage breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-28-06.

Abstract PO4-03-08: Enhanced Assessment of Clinical Behavior of TNBC and TPBC using Quantified Levels of HER2, Estrogen and Progestin Receptor Proteins and Expression of Their Cognate Genes

Abstract Background: Renewed interest in clinical relevance of low-HER2 protein in breast cancer management prompted a retrospective investigation of a unique de-identified Database of quantified biomarkers associated with patient outcomes. Currently, IHC of ER, PR and HER2 proteins provides semi-quantitative results, at times complicated by variation in methods and interpretation (cf. ASCO/CAP Guidelines). Our goal was to ascertain relationships of these clinical analytes to predict cancer relapse when quantified for protein products and cognate gene expression. Methods: Database contained 2756 quantified HER2 results by ELISA (Oncogene Sciences) or by EIA (Triton Diagnostics) of which 198 patients had associated clinical outcomes. No definition of HER2-low has been accepted for IHC, although > 50% of biopsies may be categorized as HER2-low (cf. ASCP CE Programs). Microarray results obtained for ~ 22,000 genes using RNA purified from LCM-procured carcinoma cells of 247 primary breast biopsies were analyzed. ESR1, PGR and ERBB2 gene expression levels in 276 biopsies had been validated by RTqPCR. To assess distribution and dispersion of HER2 protein, cumulative relative frequency distribution analyses were employed, focusing on cut-offs within interquartile range. Permutations and combinations of the 3 biomarkers based on IHC definitions (cf. ASCO/CAP Guidelines) were examined. Tertiles and quartiles of data sets were used to explore association between biomarker levels and clinical outcomes. Box plots depicted protein and gene expression levels, Progression-Free Survival (PFS), or Overall Survival (OS) across ER/PR/HER2 categories and compared differences using a Kruskal-Wallis ANOVA Rank Test. Cox regressions were used to contrast hazard ratios among the ER/PR/HER2 groups. Kaplan-Meier plots visualized survival rates among groups and a log-rank test detected statistical discrepancies. We investigated differences between groups for categorical variables using chi-squared tests (Fisher's exact test for non-normally distributed data), while for ordinal variables, ANOVA tests were used (Kruskal-Wallis for non-normally distributed data). Categorical variables were summarized as count (%), and ordinal variables were summarized as median [IQR]. Analyses were performed using R version 4.2.2 (Innocent and Trusting). Results: Neither quantified ER or PR alone nor ER/PR collectively were related to HER2 oncoprotein levels. Influence of menopausal status on biopsy biomarker profiles was investigated. With a median cutoff for HER2 protein, patients with ER+/PR+/HER2+ (TPBC) exhibited increased OS, whereas those with TNBC had decreased OS, of 8 combinations possible. Using tertiles and quartiles, TPBC was exhibited by 34-37% of specimens compared to TNBC, which represented 9.1-12.7% of biopsies when biomarker proteins were quantified. After qPCR data were stratified by ER/PR/HER2 status with a 50% quantile cut for HER2, 39% were TPBC and 10% were TNBC. Using microarray data with the same cutoffs, only 14% were TPBC and 17% were TNBC. Once TPBC were identified by either microarray or by qPCR, increased ESR1, PGR and ERBB2 expression collectively was associated with increased PFS and OS of patients. In general, biopsies that were TNBC or other combinations of biomarker’s gene expression correlated with poorer prognosis and overall survival. Conclusions: Quantifying levels of ER, PR and HER2 proteins as well as of ESR1, PGR and ERBB2 expression were correlated with prediction of clinical outcomes of TNBC, TPBC and patients with other biomarker subsets. Results support quantitative assessment of these biomarkers in biopsies to assess utility of the HER2-low type in personalizing breast cancer management and prediction of risk of relapse. Citation Format: James Wittliff, Michael Daniels. Enhanced Assessment of Clinical Behavior of TNBC and TPBC using Quantified Levels of HER2, Estrogen and Progestin Receptor Proteins and Expression of Their Cognate Genes [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-03-08.

Abstract PO2-20-08: Metastatic Lung Cancer Masquerading as Metaplastic Breast Cancer

Abstract Background Metaplastic breast carcinoma (MBC) is an unusual malignancy that presents a diagnostic challenge due to the presence of varying cytomorphologies that can be seen in benign and malignant tumors. We posit that metastatic disease to the breast, itself an uncommon entity, should be considered in the differential diagnosis of MBC. We report a unique case of metastatic non-small cell lung cancer (NSCLC) with an actionable driver mutation that presented as a symptomatic breast mass and was initially considered to represent MBC. Report A 74-year-old woman with a 22-pack-year smoking history presented to the breast clinic complaining of a palpable left breast mass that had grown rapidly over the previous month. Ultrasound-guided biopsy of the breast mass revealed high-grade poorly differentiated carcinoma. On immunohistochemical (IHC) evaluation, tumor cells were strongly positive for epithelial markers CAM5.2 and keratin AE1/AE3, weakly positive for breast cancer (BC) marker TRPS1, and negative for BC marker GATA3, squamous cell carcinoma markers p63 and CK5, and melanoma marker SOX10. Metaplastic triple-negative BC was diagnosed. However, concern remained for metastasis from a non-breast primary tumor due to the patient’s constitutional symptoms such as fatigue, night sweats, and 60-pound unintentional weight loss over the previous year, as well as interval development of a suspicious nodular rash on her right upper extremity. An FDG-PET-CT was obtained and demonstrated a hypermetabolic left lung consolidation (maximum SUV 33.3) measuring 7.2 cm, pulmonary nodules, and extensive thoracic lymphadenopathy. Due to rising suspicion for a primary lung tumor, additional IHC staining on the original breast biopsy was requested. Tumor cells were positive for TTF-1, consistent with metastatic lung adenocarcinoma. Tissue next-generation sequencing (NGS) identified a MET exon 14 skipping mutation, making the patient eligible for treatment with capmatinib, a first-line kinase inhibitor targeted therapy for metastatic NSCLC. At the time of this report, the patient has completed a course of palliative stereotactic body radiation therapy to the left lung and started capmatinib 400 mg BID, which she is tolerating well. Her first restaging scans after treatment initiation will be obtained one week after the time of this report. Conclusion In the absence of heightened suspicion for a non-breast primary tumor, our patient had initially received a diagnosis of triple-negative MBC. This diagnosis would have exposed her to increased treatment-related toxicities from cytotoxic chemotherapy and poor prognosis from MBC without survival benefit from targeted therapy for NSCLC. We advocate for the use of supplemental body imaging, expert and comprehensive IHC evaluation, and multidisciplinary discussion in cases of MBC and undifferentiated breast malignancy to facilitate accurate diagnosis and treatment. Citation Format: Tanmayi Pai, Marte Wasserman, Jason Lewis, Miglena Komforti, James Jakub, Augustine Lee, Yanyan Lou, Pooja Advani, Rohit Rao. Metastatic Lung Cancer Masquerading as Metaplastic Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-20-08.

Abstract PO3-09-01: Integrating pathomic and radiomic images to classify risk of subsequent events among women with DCIS

Abstract Background Multiple sources of ~omic data can be generated from women at different stages of developing breast cancer, the leading cancer diagnosed in women worldwide. Traditionally interrogation of risk factors to study associations and develop prediction models for future breast events has been limited to one or few risk factors, or summary scores of clinical and tumor characteristics. Methods to bring mammography images and breast biopsies of precancer lesions together to summarize risk of cancer developing in the breast are urgently needed. Integration of these two sources has not been performed to date, but has potential to increase accuracy of risk prediction. Approach The Repository of Archival Human Breast Tissue (RAHBT) was established in 2007 at Washington University School of Medicine (WUSM) and maintains biospecimens and medical record data of women treated with breast-conserving surgery (BCS) or mastectomy for breast cancer at WUSM and six other St Louis metropolitan hospitals between 1981-2016. Prospective follow-up of cases is achieved through health records and Siteman tumor registry. Among 1831 patients with pathologically confirmed DCIS who had no prior cancer, 174 developed breast events at least six months after initial DCIS diagnosis. For each case diagnosed between January 1998 and March 2016 with subsequent breast events, two DCIS controls were matched on race, year of diagnosis (±5 years), age (±5 years), and type of surgery. Tissue micro arrays (TMAs) are constructed after breast pathology review and processed for H&E and imaged. Breast cancer risk factor data are uniformly retrieved form the medical records at time of processing cases of DCIS. Mammogram images are retrieved for all women. Full-field digital mammograms (FFDM) are all using the same technology (Hologic). Risk factors and outcome variables: ipsilateral breast events (IBE) was defined as the development of invasive cancer or DCIS in the treated breast at least 6 months post-diagnosis. Follow-up time was calculated from the date of DCIS diagnosis to the date of first IBE, death, or last follow-up, whichever occurred first. The predictors included commonly used clinicopathological factors: age, tumor grade (high vs. low/intermediate), comedonecrosis, surgical margins (close (≤2mm) vs. negative ( >2mm)), local treatment (BCS only and mastectomy vs. BCS+radiation), and endocrine therapy. BMI, menopausal status, and ER were also available for evaluation as predictors. We limited this analysis to women with digital mammograms immediately prior to diagnosis and include 128 cases and controls. Validation cohort As the RAHBT cohort continues to be followed additional second breast events have been documented after the cut off for events identified through March 2016, and the identical procedures used to review/confirm DCIS and subsequent breast events, construct TMAs, process H&E and images, and assemble risk factor data, and the associated digital mammograms. We have 13 additional ipsilateral breast events with complete data and their controls for independently testing the model performance. Statistical methods Propose novel supervised learning approach to integrate image data from mammograms and TMA slides that accommodates agreement between multi-omics. Results 128 (cases and controls, 21.9% ipsilateral subsequent events) identified for development and internal cross validation. Median age at diagnosis was 52 and median time to subsequent breast event was 63 mo. Controlling for the clinical/pathologic risk factors (age, BMI, BI-RADs density, treatment, tumor grade, parous, menopausal status, ER status, and race) and integrating the whole mammogram and TMA pathology images, we observe a 5-yr ipsilateral AUC = 0.74; 10-yr AUC 0.75. The independent validation is ongoing. Conclusions Integrating heterogeneous multiomic data sources can generate significant improvement in long term risk prediction after initial DCIS diagnosis. Citation Format: Shih-Ting Huang, Debbie Bennett, Robert West, Graham Colditz, Shu Jiang. Integrating pathomic and radiomic images to classify risk of subsequent events among women with DCIS [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-09-01.

Abstract PO1-23-03: Management and risk of upgrade of Atypical Ductal Hyperplasia in the breast – a population-based retrospective cohort analysis

Abstract Introduction International guidelines recommend open surgery for Atypical Ductal Hyperplasia (ADH) in the breast due to risk of underestimating malignant disease. The aim here was to evaluate the management and risk for upgrade of lesions diagnosed as ADH in percutaneous breast biopsies in two Swedish institutions. Methods All women with a screen-detected or symptomatic ADH diagnosed on percutaneous biopsy between 2013-2022 at Sundsvall and Umeå University Hospitals were included. Women with lesions classified as Breast imaging-reporting and data system (BI-RADS) 5 (highly suspicious) or 6 (confirmed malignancy) were excluded. Data were retrieved from medical records and histopathology reports. Odds ratio (OR) and 95 % confidence intervals (CI) for upgrade to malignant diagnosis after surgery was calculated by logistic regression analysis. Results Altogether, 101 women were included, mean age 56.1 years (range 36-93 years). Most women were selected from the national mammography screening program due to microcalcifications. Biopsies were performed with vacuum-assisted biopsy (VAB)(60.4%) or core-needle biopsy (CNB)(39.6%). Forty-eight women (47.5%) underwent surgery. Presence of a first degree relative with breast cancer (p < 0.001), more extensive microcalcifications (p=0.01), biopsies with ADH bordering DCIS (p=0.01) and CNB as opposed to VAB (p=0.02) increased the likelihood of surgical excision. Among the women undergoing surgery, eleven were upgraded to Ductal Carcinoma in Situ and seven to invasive breast cancer (overall upgrade rate 37.5%). In these women, no variable correlating to risk of upgrade in the surgical specimen was identified. After median 74 months of follow-up (range 4-105 months), one out of 53 women managed conservatively (1.9%) developed subsequent ipsilateral DCIS. Conclusion The upgrade rate to carcinoma was 37.5% after surgery while the estimated 5-year risk of ipsilateral upgrade in women managed conservatively was 1.9%. Acknowledging the short median follow-up time, these results indicate that the selection for non-surgical management in a subset of women was appropriate. Summary of histopathological results after surgical excision of ADH Citation Format: Charlotta Wadsten, Gunilla Rask. Management and risk of upgrade of Atypical Ductal Hyperplasia in the breast – a population-based retrospective cohort analysis [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-23-03.

Abstract PO4-10-07: Understanding Psychological distress in patients prior to breast cancer diagnosis:Mixed Methods Study

Abstract Purpose:While the association between diagnosis of breast cancer and post-diagnosis psychological distress has been well documented, data regarding pre-diagnosis psychological distress in the breast cancer population are limited. The purpose of the current study is to measure the distress levels of patients prior to breast cancer diagnosis, to identify the categories of distress they have, and describe the experience of distress of patients before diagnosis. Methods: This study uses a mixed research method of cross-sectional survey and qualitative interviews. In the quantitative part, a cross-sectional survey of 118 patients with completed breast biopsies awaiting pathological diagnosis was conducted using the National Comprehensive Cancer Network’s (NCCN’s) Distress Thermometer(DT) and Problem List (PL), In the qualitative part, 15 patients were invited using convenient and purposive sampling. Data was collected using a semi-structured face-to-face interview and recorded. The transcribed text was analyzed using Colaizzi's phenomenological method. Results: The results reveal that 63.6% of patients reported a higher level of psychological distress (n=75, scoring≥4).Most patients had emotional (98%) or physical (64%) problems. Among these, worry or anxiety (47.5%), fear (33.1%), finances (21.2%), sadness and depression(18.6%), and grief or loss(15.3%) were the most frequently reported problems. Multivariate logistic regression analysis showed that the factors associated with psychological distress before the diagnosis of breast cancer patients were age, education level. The experience of patients before diagnosis emerged five themes: Very high psychological distress index; Strong uncertainty; The demand of information; Guilt for the family; Hoped for psychological support from the health care team. Conclusions: Psychological distress is prevalent prior to breast cancer diagnosis and may merit early intervention. Understanding patients’ distress may help guide future psychosocial needs assessments and interventions to promote patient quality of life. Table 1 Sample characteristics (n=118). Table 2 Univariate analysis of predictors associated with psychological distress Table 3 The binary logistic regression model of psychological distress Citation Format: Yan Gao, Jinnan Gao. Understanding Psychological distress in patients prior to breast cancer diagnosis:Mixed Methods Study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-10-07.

Abstract PO2-13-01: Weight change in early breast cancer-based baseline body mass index and treatment

Abstract Background: Early-stage breast cancer is a common condition with significant effects on health, both as a result of treatment and underlying conditions. Breast cancer has been associated with obesity, weight gain, and diabetes. Little is known about changes in weight after breast cancer diagnoses based on baseline weight. Additionally, weight change may differ due to treatments, such as chemotherapy or hormone therapy. Methods: A retrospective study was conducted using deidentified electronic medical records data from a national health informatics provider and insurer database to identify the cohort. The cohort inclusion criteria included women with a diagnosis of breast cancer, a breast biopsy procedure, and a breast cancer surgery within a 1-year period of time from 2010-2018. Body-mass index (BMI) within 1 month of initial biopsy was collected, and weight at 6 months and 1 year after initial biopsy was used to calculate the percentage change in weight. Treatment with chemotherapy within 1 year of diagnosis and hormone therapy within 6 months was also collected. Patients were divided into standard BMI categories as well as BMI >25 vs. ≤25. ANOVA was used to compare outcomes of weight change based on BMI, chemotherapy, and hormone therapy. Linear regression was used to analyze the effects of age, BMI, chemotherapy, and hormone therapy with weight change at 1 year. Results: In 4,541 patients diagnosed with breast cancer, 3,896 patients had weight available at 6 months and 3,406 had weight available at 1 year. Mean age at diagnosis was 61.5 years (standard deviation (SD) 12.4) with mean BMI of 29.9 at baseline (SD 7.3) and weight of 79.5 kg (SD 20.2). Chemotherapy was administered in 1206 patients (26.6%) and hormone therapy in 1,644 (36.2%) with 210 (4.6%) receiving both therapies. Overall, patients lost a mean of 0.6 kg (0.5% change, SD 5.1) at 6 months and 0.6 kg at 1 year (0.4% change, SD 5.7). At one year, patients with BMI < 25 gained 0.74% of body weight vs. lost 1.1% of weight in BMI >25 (p< 0.001). Patients treated with chemotherapy lost 1.4% body weight vs. lost 0.23% in patients without chemotherapy (p< 0.001) and patients treated with hormone therapy lost 0.12% of body weight vs. lost 1.3% without hormone therapy. A linear regression model including age, BMI, chemotherapy, and hormone therapy to explain weight change at one year was statistically significantly better than a baseline model at explaining the weight change at one year [F(4,2474)=61.05]. Increasing age (b=-0.125; t=-10.546; p< .001; 95% CI for beta :0.14 -0.10), BMI (b=-0.178; t=-9.428; p< .001; 95%CI :0.22 -0.14), and chemotherapy (b=-1.643; t=-4.645; p< .001; 95% CI: 2.4 -0.95) were all significant predictors associated with weight loss at one year while hormone therapy was also a significant predictor but was associated with weight gain (b=0.846; t=2.428; p=.015; 95% CI: 0.16-1.5). Conclusions: Women with early breast cancer experienced significant changes in weight in the year after diagnosis. Women with lower BMI gained weight while those with BMI >25 lost weight. Increasing age, BMI, and treatment with chemotherapy was associated with weight loss while use of hormone therapy was associated with weight gain. Further study of weight changes after breast cancer diagnosis are appropriate to understand outcomes and mitigate effects of treatments. Table 1: Percentage weight change across BMI groups by chemotherapy use Citation Format: Martin Schoen, Deepika Gopukumar, Abhilash Akula, Kaitlin Farrell, Aimee Schad, Leslie Hinyard. Weight change in early breast cancer-based baseline body mass index and treatment [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-13-01.

Abstract PO5-19-12: Innovative Trial Design: ARTIDIS Nanomechanical Generated Measurements for Early Breast Lesions (ANGEL) - Multicentre Study

Abstract Background: The diagnosis of breast cancer based on histopathology of core needle biopsies and the delineation into breast cancer subtypes to drive clinical treatment decisions can be time consuming and cause patient (and clinician) anxiety. Alternative, near patient, approaches to conventional diagnostic pathways would be desirable to drive diagnostic and therapeutic planning. This study harnesses the novel concept of evaluating diagnostic cores for nanomechanical features at the time of core biopsy. Clinical manifestations of disease are often accompanied by biomechanical alterations at sub-/cellular, extracellular, tissue and organ level. Mechanical properties of cancer cells and their microenvironment play a critical role in cancer invasion, progression, and immune cell infiltration. Ultrastructural (sub-) cellular alterations (nanoscale level), including the remodulation and alteration of cellular cytoskeleton dynamics, contribute to altered mechanical state of cancer cells, and lead to increased deformability and motility of soft cancer cells to overcome stromal barrier, and spread into the adjacent tissues and distant sites in the body. This results in a direct mechanistic correlation between nanomechanical properties and clinical outcome in cancer tissues. The ARTIDIS Nanomechanical Generated measurements for Early Lesions (ANGEL) Study will prospectively evaluate the efficacy of the ARTIDIS system as an aid to diagnosis, as well as subtyping breast cancer and predicting clinical outcomes based on tissue nanomechanics, particularly in the context of neoadjuvant therapy (NAT). Methods: The study seeks to validate the predictive power of the nanomechanical signature, a unique tissue biomarker reflecting the tissue phenotype, by comparing it to standard histological assessment. A projected cohort of 2,705 patients will be enrolled, from diverse ethnic and socioeconomic backgrounds, with benign or malignant breast conditions undergoing diagnostic core biopsy. A single core biopsy (gauge agnostic) is placed in a cassette and subjected to thousands of mechanical measurements at the “nano” scale over a period of 1-3 hours. The ARTIDIS technology builds upon the Atomic Force Microscopy platform to non-disruptively detect up to 17 different nanomechanical parameters in soft tissues with a subcellular resolution. The same core biopsy can then undergo fixation and conventional histopathological analyses for comparison with the final pathology. The primary aim is to confirm the potential of the ARTIDIS system in diagnosis (benign vs malignant) and secondarily address whether the nanomechanical signature can differentiate subtypes of breast cancer, associate with clinical outcome, and guide treatment decisions. Particularly, we will investigate ARTIDIS potential as a predictor of treatment response for patients receiving NAT. Results: The multicenter ANGEL study is a prospective investigation that builds upon previous clinical data from the NANO study at the University Hospital Basel (Switzerland) and is designed to demonstrate the power of using a nanomechanical signature to evaluate breast biopsies within a routine clinical setting in a multicenter setting. The data will be used to develop ARTIDIS as an aid to diagnosis, as well as NEO Match test applications to predict and guide response to NAT. Conclusion: This study presents the first of its kind as a direct prospective, multi-center based clinical translation of the Physics of Cancer findings into clinical settings. This innovative trial design allows the prospective development of ARTIDIS as an aid to diagnosis and NAT outcome prediction and therapy guidance applications. Citation Format: Karla Sepulveda, Ashley Roark, Sagar Dhamne, Chandandeep Nagi, Ivan Marin, Iqbal Tabish, Susanne G. Hilsenbeck Hilsenbeck, Sara Nizzero, Mariam Gachechiladze, Tobias A Appenzeller, Marko Loparic, Marija Plodinec, Alastair Thompson. Innovative Trial Design: ARTIDIS Nanomechanical Generated Measurements for Early Breast Lesions (ANGEL) - Multicentre Study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-19-12.

Abstract PO1-25-11: Deciphering biological differences between normal breast tissues in men and women using single cell sequencing and in vitro modeling

Abstract Breast cancer in men is relatively rare but outcome from the disease is worse than in women. Although 87% breast cancers in men are Estrogen Receptor-positive (ER+), anti-estrogen therapy is less efficacious in men compared to women with similar breast cancer subtype. Recent genomic analysis of breast tumors in men and women have identified overlapping as well as unique genomic aberrations in breast tumors of men. It is unclear whether genomic aberrations enriched in breast cancers of men uniquely affect the biology and thus alter response to antiestrogen therapy. This lack of knowledge is mainly due to scarcity of model systems. To overcome this limitation, we collected ultrasound guided breast biopsies of healthy men and characterized breast epithelial cells grown from these biopsies. Biopsies were also subjected to single nuclei sequencing. Single nuclei breast atlas of men is currently being superimposed on single nuclei breast atlas generated from breast biopsies of healthy women to determine whether distinct cell types exist in men and to distinguish ductal and lobular breast epithelial cells. Breast epithelial cells of men expressed higher levels of ER compared to similarly propagated breast epithelial cells of women. Expression of ER in a subpopulation of cultured breast epithelial cells was confirmed by immunofluorescence. Among the pioneer factors that determine genome wide binding pattern of ER, TBX3 is expressed at a higher level but FOXA1 is expressed at a lower level in breast epithelial cells of men compared to women. Comparative RNA-seq analysis of breast epithelial cells of men and women revealed elevated non-genomic ER signaling in men compared to women, which could be responsible for limited response of breast tumors of men to anti-estrogen therapy. Additional pathways uniquely upregulated in breast epithelial cells of men include non-canonical Wnt, HIF1A, JUN, NF-kB, TGFb, and FOXO1 signaling. Expectedly, breast epithelial cells of men expressed 15 Y chromosome associated genes including the epigenetic regulators KDM5D and UTY, which have recently been shown to be responsible for sex-specific differences in outcome from other cancer types and loss of Y chromosome could be driver event in certain cancer types. We have created immortalized and transformed variants of breast epithelial cells of men to further aid in mechanistic investigation and drug discovery. Furthermore, our tissue bank currently has breast biopsies of ~30 healthy men to be used as controls for breast cancer studies in men. To our knowledge, this is the first model system to study breast cancer in men starting with breast tissues of healthy men. Citation Format: Poornima Bhat-Nakshatri, Benjamin Fischer, Aditi Khatpe, Adedeji Adebayo, Hongyu Gao, Yunlong Liu, Michele Cote, Harikrishna Nakshatri. Deciphering biological differences between normal breast tissues in men and women using single cell sequencing and in vitro modeling [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-25-11.

Abstract PO4-19-10: Selective Avoidance of Sentinel Lymph Node Biopsy After Neoadjuvant Chemotherapy In HER-2 Positive/Triple Negative Breast Cancer Patients With Excellent Radiologic Response to the Breast and Axilla

Abstract Background Neoadjuvant chemotherapy (NACT) for breast cancer (BC) is downstaging inoperable tumors into operable tumors and de-escalating breast/axillary surgery. According to advanced NACT, dual human epidermal growth factor-2 (HER2) blockage in HER2-positive BC, carboplatin, and immunotherapy in triple-negative breast cancer (TNBC) revealed pathologic complete response (ypCR) rates of up to 68% and 80%, the indications for NACT have expanded to early BC and the expected ypCR rate has increased. Therefore, it may be reasonable to consider omitting surgery in cases with excellent responses to NACT. Although sentinel lymph node biopsy (SLNB) is minimally invasive, some patients still experience complications such as lymphedema, pain, sensory loss, and axillary web syndrome. Several recent retrospective studies and pilot prospective studies have reported axillary pathologic complete response (ApCR) is highly correlated with breast pathologic complete response (BpCR). In cN0 with HER2+ BC and TNBC, the ApCR rate in BpCR after NACT was reported up to 100%, and in cN1 with HER2+ BC and TNBC, the ApCR rate in BpCR after NACT was reported about 85%. There are many studies predicting BpCR using radiologic imaging such as breast mammography (MMG), ultrasonography (USG), and magnetic resonance imaging (MRI). However, the combination of tri-modality (MMG, USG, MRI) could not confirm BpCR. The current study is screened in cT1-3N0-1M0, HER2+ or TNBC, and planned breast-conserving surgery (BCS) patients after NACT with excellent response at the combination of tri-modality imaging (breast MMG, breast USG, breast MRI) and with expected BpCR at physical examination. Methods Trial design The ASLAN trial is a prospective, multicenter, single-arm, clinical study. The five tertiary care hospitals in South Korea are participating which are members of the Korean Breast Cancer Study Group (KBCSG). Eligibility Inclusion criteria: women aged 20-69; cT1-3N0-1M0; HER2+ or TNBC (defined by ER-negative (< 10% positive cells in IHC) and PR-negative (< 10% positive cells in IHC)); expected complete remission at physical examination and radiological expected Tumor size ≤ 2cm or non-mass enhancement ≤ 4cm at breast MRI after standard NACT; planned breast-conserving surgery (BCS) with whole-breast irradiation; ECOG performance status 0-1. Exclusion criteria: SLNB before NACT; previous axillary surgery; bilateral BC; pregnancy. Intervention In eligible patients, BCS was performed. After BCS, patients who showed BpCR are enrolled with the omission of SLNB. Patients with no BpCR proceed with routine axillary surgery. Sample size calculation The assumption for an acceptable 5-year RFS ≥84% is based on previous study findings. The calculated total case number for per-protocol analysis is N=178. By Jun 2023, 153 patients had been enrolled and the target accrual of 178 patients is expected to be complete by Dec 2023. Study outcomes Primary endpoint: 5-year recurrence-free survival. Secondary endpoint: local recurrence-free survival, breast cancer-specific survival, overall survival, ipsilateral axillary recurrence interval, distant metastasis-free survival, contralateral breast-free survival, re-operation rate according to breast biopsy after NACT, adverse event, and quality of life. Accrual Plans The first patient was enrolled on Sep 2021. Among 223 patients who were screened, 153 patients have been enrolled in Jun 2023. We plan to complete the target accrual by Dec 2023. Conclusion The primary aim of the ASLAN trial is to demonstrate the oncologic safety of omitting axillary surgery for the excellent response after NACT in HER2+ or TNBC, early breast cancer patients undergoing BCS and adjuvant RT ASLAN trial, altogether with the EUBREAST-01 and ASCIS trials, will answer the very important question that may alter the axillary surgery in highly selected patients after NACT Citation Format: Jai Min Ryu, Wonshik Han, Han-Byoel Lee, Sung Gwe Ahn, Hee Jeong Kim, Hyung Seok Park, Ji Soo Choi, Hyunjun Lee, Hae Young Kim, Jeong Eon Lee. Selective Avoidance of Sentinel Lymph Node Biopsy After Neoadjuvant Chemotherapy In HER-2 Positive/Triple Negative Breast Cancer Patients With Excellent Radiologic Response to the Breast and Axilla [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-19-10.

Abstract PO2-20-09: Hiding in plain sight: A heterogeneous response in a patient with metastatic HR+/HER2- breast cancer

Abstract INTRODUCTION: Metastatic breast cancer is an infamously heterogeneous disease—characterized by a range of clinical presentations and treatment responses. In light of this heterogeneity, ASCO guidelines recommend patients with new, accessible metastatic tumors undergo a biopsy to inform treatment decisions. Here, we present a patient with HR+/HER2- disease with a long history of unusually heterogeneous responses—and a repeat metastatic biopsy that provided an answer. CASE: A 55-year-old woman presented for consultation of treatment-refractory metastatic breast cancer. She was originally diagnosed with a right-sided Stage III HR+/HER2- invasive ductal carcinoma (IDC) at the age of 33. Upon staging, she was incidentally found to have a right lower-lobe lung carcinoid tumor that was removed by lobectomy. She underwent a partial mastectomy, axillary lymph node dissection, followed by adjuvant chemo- and radiation therapy. She tolerated one week of tamoxifen which was discontinued due to adverse effects. Fifteen years later, screening mammography revealed a suspicious lesion in the right breast—biopsy consistent with a new IDC. She underwent bilateral mastectomies which showed a pT1cNxM0 G2 IDC with associated DCIS (ER+/PR+/HER2 IHC 2+, FISH-negative, Oncotype RS 12). Genetic testing was negative. The patient trialed adjuvant tamoxifen, which was discontinued due to repeat adverse effects. Two years later, rising tumor markers prompted restaging scans that demonstrated an enlarging liver lesion. Liver biopsy was consistent with metastatic adenocarcinoma of the breast (ER+/PR+/HER2 IHC 0), GATA3 positive. Patient was started on letrozole with lupron and palbociclib with disease control for two years until progression in the bone, prompting a switch of letrozole to fulvestrant with continued palbociclib. Her disease was stable for two additional years until progression of multiple liver lesions. She was then started on single-agent paclitaxel. At this point, she was seen in our office for consultation and next-line therapy options. Repeat staging scans showed heterogeneous response in the liver with overall progression. ctDNA testing revealed a mutation in MEN1 (p.Q354*, 2.8% VAF) without other actionable alterations. Patient opted to enroll into a clinical trial of an experimental ER-antagonist but experienced progression of her liver lesions on first staging scans. A second liver biopsy was performed on a progressive lesion which showed ER-/PR-/HER2- disease. She opted to enroll into a Phase 1b/2 trial with sacituzumab govitecan-hziy in combination with a PARPi. Staging scans again showed a mixed response in the liver. Given a history of mixed responses and discordant receptor staining, the differential diagnosis included loss of hormone receptor expression in the breast carcinoma versus metastases from an occult neoplasm. Additional immunohistochemical studies were performed on a subsequent liver biopsy showing positivity for chromogranin, synaptophysin, and INSM1, and negative results for ER, PR, GATA3, and TRPS1. Next-generation sequencing of the progressive lesion revealed a MEN1 SNV (p.Q354*, VAF 82%) as well as loss of 11q (MEN1 locus) suggestive of biallelic loss of MEN1—providing molecular evidence of a metastatic carcinoid tumor. A history of mixed response in the liver was concluded to be two coexisting neoplasms—a metastatic HR+/HER2- breast cancer as well as a late recurrence of a right-lower lobe carcinoid tumor from 22 years prior. DISCUSSION: The unanticipated discovery of an occult, coexisting neoplasm in the setting of a metastatic HR+/HER2- breast cancer illustrates the value of meticulous pathological review, repeat molecular testing and the use of next-generation diagnostic tools such as tumor sequencing in the advanced setting—particularly when a clinical story defies conventional expectations—to personalize care and optimize oncologic management in the face of complex biology. Citation Format: Nolan Priedigkeit, Jane Brock, Olivia Cunningham, Molly Skeffington, Melissa Hughes, Nancy Lin, Susan Lester, Heather Parsons. Hiding in plain sight: A heterogeneous response in a patient with metastatic HR+/HER2- breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-20-09.

Abstract GS01-06: Advancing Evidence of the Associations Between Specific Benign Breast Diagnoses and Future Breast Cancer RIsk

Abstract Background: Benign breast disease (BBD) is a common breast biopsy finding encompassing a diverse spectrum of diagnoses. Breast cancer risk associated with many specific BBD diagnoses and their joint associations with breast density have not been extensively studied. We estimate the future risk of invasive breast cancer associated with specific BBD diagnoses typically categorized into the broad category of proliferative lesions without atypia (PWoA) and evaluate whether associations differ by breast density or by presence of calcifications. Methods: We included 1,313,943 women ages 40-79 years who underwent 5,282,063 mammograms in the Breast Cancer Surveillance Consortium from 1996 to 2019 with no prior history of breast cancer. We fit a Cox proportional hazards model to estimate hazard ratios associated with each combination of PWoA BBD diagnoses, whether calcifications were present on biopsy, and breast density. We used classification trees to group combinations of PWoA diagnoses, breast density, age groups, and presence of calcifications with similar magnitudes of associations with 5-year risk of invasive breast cancer. Results: Compared with women with a PWoA BBD diagnosis without calcifications, presence of calcifications significantly elevated risk for breast cancer (HR=1.19, 95% CI = 1.02 to 1.41, P=0.03). Considering specific PWoA diagnoses, classification trees identified groups of women with higher and lower invasive cancer risk than expected risk for all PWoA combined. Among women ages 60-79 years with heterogeneously or extremely dense breasts, the 2.6% of women with any PWoA diagnosis, except papillomatosis, were at high invasive breast cancer risk (5-year risk >2.5%) (Table 1). Among women ages 40-59 years with dense breasts, presence of calcifications with papillomas, usual ductal hyperplasia, columnar cell hyperplasia, or PWoA NOS diagnoses put these women at high risk (5-year risk >2.5%) compared to women with the same BBD diagnoses without calcifications who were at intermediate or average risk (1-2.49%) (Table 1). Among women ages 60-79 years with non-dense breasts, the 1.6% of women with papilloma, usual ductal hyperplasia, radial scar, or PWoA NOS diagnoses were at high breast cancer risk (Table 2). Among women ages 40-59 years with non-dense breasts, presence of calcifications with usual ductal hyperplasia or PwoA NOS diagnoses put these women at intermediate risk (1.67-2.49%) compared to women with these BBD diagnoses without calcifications who were at average risk (1-1.66%) (Table 2). Women 60-79 years with fatty breasts were at intermediate 5-year risk if they had papillomas, usual ductal hyperplasia, or PWoA NOS diagnoses. Women 40-59 years with fatty breasts were at low risk of breast cancer regardless of PWoA diagnosis (Table 2). Conclusion: Specific BBD diagnoses and the presence of calcifications can change a woman’s predicted 5-year breast cancer risk compared to broad BBD categories alone. This information could be incorporated into risk prediction models to improve model accuracy. Citation Format: Olivia Sattayapiwat, Karla Kerlikowske, Donald Weaver, Alexander Borowsky, Theresa Keegan, Brian Sprague, Diana Miglioretti. Advancing Evidence of the Associations Between Specific Benign Breast Diagnoses and Future Breast Cancer RIsk [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr GS01-06.

Abstract PO5-27-11: A COMPARATIVE STUDY OF DIAGNOSTICS MADE BY FINE NEEDLE ASPIRATION (FNA) BIOPSY VERSUS TRU-CUT FOR BREAST PATHOLOGY IN A ONE STOP CLINIC PROGRAM IN MEDELLIN, COLOMBIA

Abstract Breast cancer is the leading cause of morbidity and mortality among women in Colombia due to non-communicable chronic diseases. This has prompted health insurance companies to develop innovative initiatives to mitigate these negative outcomes. Since September 2018, Ayudas Diagnósticas SURA, in alliance with the Gustave Roussy Hospital and General Electric Healthcare has promoted a “One-stop clinic” program called: “TIEMPO PARA TI”. One of the primary challenges was to demonstrate that breast cytology, based on the Yokohama guidelines approved by The International Academy of Cytology has a high sensitivity, specificity, and diagnostic accuracy. The Yokohama system for classifying breast cytology is comprised of five categories: C1 not satisfactory, C2 benign, C3 atypical, C4 malignancy suspected, and C5 malignant. From September 2018 to December 2022, consecutive patients referred for breast biopsy and suspected of having breast cancer underwent triple assessment of breast tumor and were included in this retrospective study. Descriptive analysis was made using STATA v17 software to compare fine needle aspiration (FNA) biopsy versus Tru-cut. A total of 14,501 patients were included, 14.398 FNA and 14.401 trucut biopsies were performed. The comparative analysis showed a 99% concordance between categories 2, which correspond to benign lesions and 96.7% between categories 5, which correspond to malignant lesions. Our findings demonstrate that a well-executed FNA biopsy is not inferior to a trucut biopsy, as revealed by the Yokohama system, and offers significant advantages, such as cost-effectiveness and prompt diagnosis. Both techniques should be used with caution, considering their advantages and disadvantages. Citation Format: Sara Gil, Carlos Agudelo, Jorge Castaño, Melissa Naranjo, Clara Piedrahita, Daniel Wilches, Kelly Corredor. A COMPARATIVE STUDY OF DIAGNOSTICS MADE BY FINE NEEDLE ASPIRATION (FNA) BIOPSY VERSUS TRU-CUT FOR BREAST PATHOLOGY IN A ONE STOP CLINIC PROGRAM IN MEDELLIN, COLOMBIA [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-27-11.

Abstract PO3-22-07: Predicting Additional Axillary Metastases in Breast Cancer Patients with Positive Targeted Axillary Dissection Lymph Nodes after Neoadjuvant Treatment

Abstract Background: Neoadjuvant chemotherapy (NACT) is increasingly used for axillary downstaging in clinically node-positive breast cancer patients, and a considerable proportion achieves axillary pathological complete response (ax-pCR). After NACT, axillary staging can be done by targeted axillary dissection (TAD). In case of metastases at TAD, axillary lymph node dissection (ALND) is offered regardless of metastases size. This contrasts primary surgery, where small sentinel node metastases (ypN0(i) and ypN1mi) and ≤2 positive sentinel nodes do not confer ALND, although a proportion of patients with small metastases have additional metastatic lymph nodes (LNs) in the axilla. So far, the residual metastatic burden in the axilla when TAD LNs are positive after NACT is unknown. If subgroups of patients with low residual metastatic burden in the axilla (non-TAD LNs) could be identified, these subgroups may be offered de-escalated axillary treatment. Therefore, we investigated the risk of residual metastatic burden in the axilla when the TAD LNs harbored metastases. Methods: We retrospectively retrieved DBCG data on patients staged by TAD after NACT in Denmark between 1.1.2016-31.8.2021. We registered: age, breast biopsy date, type of surgery, type of axillary surgery, count of LNs, sentinel nodes, and marked lymph nodes with and without metastases, including metastasis size, breast tumor histology and receptor subtype, breast tumor size at diagnosis and in the surgical specimen, malignancy grade and type of neoadjuvant treatment. We excluded patients with inflammatory breast cancer, < 4/>8 cycles of NACT, or a non-standard NACT regimen. The primary outcome was risk factors for having high ( >3), low (1-3), or no residual metastatic burden in the axilla when the TAD LNs harbored metastases. We modeled risk factors for both high and low residual metastatic burden in the axilla using multivariable logistic regression and constructed risk models based on the regression coefficients. Results: We identified 1626 patients receiving NACT and TAD in the inclusion period. After excluding ineligible patients and patients who achieved ax-pCR with no subsequent ALND (46%), the study included 383 patients with positive LNs at TAD for further analysis: thereof 188, 127, and 68 with 0, 1-3 and >3 positive non-TAD LNs, respectively. In the adjusted logistic regression analysis, we found that breast pCR (OR= 0.06, 95% CI < .01-0.41, p < .001) and a low proportion of positive TAD LNs (0-66% vs >66%) (OR=0.32, 95% CI 0.17-0.58, p = < .001) were associated with low risk of high residual metastatic burden in the axilla. Patients with one or both low-risk factors present had an 8% (14 of 176 patients) risk of high residual metastatic burden in the axilla. The predictive value of the model for having < 3 non-TAD LN metastases was 92%. When analyzing the 315 patients with ≤3 positive non-TAD LNs, the adjusted logistic regression analysis of 1-3 vs 0 positive non-TAD LNs showed that ypN0(i) in the TAD LN (OR=0.14, 95% CI 0.04-0.53, p = 0.002), small tumor size at diagnosis (20-49 mm vs ≥ 50 mm) (OR = 0.29, 95% CI 0.14-0.60, p = 0.002), breast pCR (OR= 0.38, 95% CI 0.15-0.98, p = 0.04) and low proportion of positive TAD LNs (33-66% vs >66%) (OR= 0.46, 95% CI 0.27-0.77, p = 0.01) were associated with no residual metastases in the axilla. Using these risk factors, 19% (11/58) of the patients in the lowest risk quartile had further metastatic spread to the axilla. Conclusion: Based on an extensive breast cancer registry, we find that breast pCR, low proportion of positive TAD LNs, small metastases, and small tumor size are associated with low risk of residual metastatic LNs in the axilla when the TAD LNs are positive after NACT. With these risk factors, we propose two models to identify patients with low non-TAD residual metastatic burden and patients with a high likelihood of no further metastases. The models can guide breast surgeons in de-escalating axillary treatment in these groups. Citation Format: Frederikke Munck, Maj-Britt Jensen, Ilse Vejborg, Maria Gerlach, Maja Maraldo, Niels Kroman, Tove Tvedskov. Predicting Additional Axillary Metastases in Breast Cancer Patients with Positive Targeted Axillary Dissection Lymph Nodes after Neoadjuvant Treatment [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-22-07.

Abstract PO1-20-08: Primary breast implant-associated squamous cell carcinoma with subsequent TEMPUS testing and failure of immunotherapy

Abstract Primary squamous cell carcinoma of the breast is a rare entity, and there are a limited number of cases in the literature describing squamous cell carcinoma arising from breast implants. It has been hypothesized that these implant-associated cancers may arise from epithelialization of the implant capsule followed by chronic inflammation. None of the cases in the literature were treated with immunotherapy. We present a case of an aggressive, primary sarcomatoid squamous cell carcinoma of the breast arising from a breast implant that was treated unsuccessfully with simultaneous chemotherapy and immunotherapy following TEMPUS testing. Introduction: Breast augmentation is the most common plastic surgery procedure performed worldwide, with more than 300,000 done in the United States every year. While breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is extensively discussed in recent literature, other breast implant-associated cancers are rarer and less studied. Breast implant-associated squamous cell carcinoma (BIA-SCC) specifically is an extremely rare complication of breast augmentation and no guidelines for treatment exist. The American Society of Plastic Surgeons (ASPS) released a statement on BIA-SCC on 9/2022 following a safety communication from the FDA, and it is recommended health care providers submit case reports of BIA-SCC to a patient registry. Case study: We present the case of a female patient who underwent bilateral breast augmentation in 2006 with Mcghan textured, pre-pectoral, areolar saline implants. In 2022, she presented with swelling and a lump in her breast and underwent bilateral breast implant removal with capsulectomy. Pathology showed triple negative sarcomatoid squamous cell carcinoma of the right breast capsule. TEMPUS testing on the breast biopsy revealed a PIK3CA mutation and PD-L1 negative status. Her case was discussed with a multi-disciplinary team including plastic surgery, multiple oncologists, and radiation oncology and her clinical picture was determined to be most consistent with BIA-SCC. Based on the KEYNOTE-522 study, she was determined to be a candidate for neoadjuvant therapy with pembrolizumab and chemotherapy as she was newly diagnosed, previously untreated, nonmetastatic, and had a triple negative tumor. She received two cycles of carboplatin, paclitaxel, and pembrolizumab but unfortunately rapidly progressed with chest wall extension, multiple new pulmonary nodules, worsening lymphadenopathy, right ventricular tumor thrombus, and new malignant pleural effusion and was transitioned to hospice. Discussion: Seven cases of BIA-SCC, one case of squamous cell carcinoma (SCC) after liquid silicone injection augmentation, one case of squamous metaplasia on the breast implant capsule, and one case of epithelization of the breast implant capsule have been previously described in the literature (Table 1). None of the available cases of BIA-SCC report TEMPUS testing, and none of the patients were treated with immunotherapy. The origin of BIA-SCC is unclear, but several theories have been described including chronic inflammation leading to conversion of epithelial tissue on the capsule to SCC. It is unknown how the breast implant capsule might become epithelialized to begin with – introduction of epithelium intraoperatively during augmentation, rupture of epidermal cysts, existence of epithelium in the area from a childhood injury or from birth, or epithelization from chronic shear forces from the augmentation or leakage of the implant are all possibilities. With the ongoing data gathering through the FDA patient registry, we will continue to learn more about these rare cancers and potentially get further insight into their origins. Table 1 An overview of cases of BIA-SCC in the literature Citation Format: Emily Podany, Katherine Clifton. Primary breast implant-associated squamous cell carcinoma with subsequent TEMPUS testing and failure of immunotherapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-20-08.

Automatic Classification of Cancerous Masses in Digital Mammograms Using Curvelet Analysis and Hybrid Genetic Algorithm-Artificial Neural Network Model

Background: Mammography is the most fundamental and widely used method for detecting breast abnormalities. Distinguishing malignant from benign lesions requires extracting relevant information, which can be challenging and time-consuming for radiologists. Computer-aided diagnosis (CAD) techniques can serve as complementary diagnostic tools, assisting radiologists in the early detection and analysis of abnormalities in mammograms. Objectives: This study aimed to propose a CAD system for extracting significant features of abnormalities in breast mammograms using Curvelet transform and fractal analysis, and classifying breast tumors as malignant or benign based on the calculated features. Patients and Methods: In this study, an efficient feature extraction method was applied, utilizing Curvelet transform and fractal analysis, on a dataset comprising 113 abnormal images from the Mammographic Image Analysis Society (MIAS) database, which included 62 benign and 51 malignant cases. The method yielded 575 features, but due to potential irrelevance or redundancy, a multi-objective optimization (MOO) approach based on a genetic algorithm (GA) for an artificial neural network (ANN), named GA-MOO-ANN, was proposed to obtain and focus on an optimal and effective feature set. As a result of this approach, a set of 17 efficient features was extracted. The proposed algorithm was implemented in MATLAB 2014a, and the performance metrics were calculated using 6-fold cross-validation. Results: The experimental results demonstrated exceptional performance, with an accuracy (Acc) of 98.2%, specificity (Sp) of 100%, sensitivity (Se) of 96.8%, positive predictive value (PPV) of 100%, negative predictive value (NPV) of 96.2%, and an impressive area under the curve (AUC) of 0.98, providing comparable results to other recent methods. Conclusion: The current findings suggest that the proposed method could be a valuable tool for breast cancer diagnosis, potentially reducing the number of unnecessary breast biopsies. This method may lead to more efficient patient evaluation and earlier detection of breast tumors.

Coupling of the expression of proliferation and epithelialmesenchymal transition markers with the histidine-rich glycoprotein HRG mRNA expression in breast diseases

Non-malignant breast diseases (NMBD) may increase the risk of developing a malignant neoplasm. Therefore, it seems relevant to search for criteria for cell malignancy in NMBD. Aim of the study was to investigate the relationship between expression of proliferation and epithelial-mesenchymal transition (EMT) markers and histidine-rich glycoprotein (HRG) mRNA in breast diseases. Material and methods. In breast biopsy specimens of 37 patients with invasive carcinoma of a non-specific type (ICNT) and 17 patients with NMBD expression of proliferation markers (Ki-67, cyclin D1 (CCND1)) and EMT markers (E-cadherin (CDH1), type II collagen (CII) and β1-integrin (CD29)) was determined immunohistochemically. HRG mRNA expression was estimated using real time PCR. Results. HRG mRNA expression was detected in 91.9 % cases (34 of 37) in ICNT, 82.4 % (14 of 17) in NMBD and in the latter case was inversely related to the expression of CDH1, CD29 and Ki-67. A direct relationship has been established between the presence of Ki-67 and CCND1, CII, between CCND1 and CD29 in NMBD. In patients with ICNT, a direct correlation was found between the HRG mRNA expression and the presence of CII, and an inverse correlation between the number of cells containing CII and CD29. It was found that in ICNT and NMBD with the presence of HRG mRNA expression, the CDH1 expression is less than in its absence. Conclusions. Indicators of HRG mRNA expression in NMBD, combined with the assessment of proliferation and EMT markers, can be useful in developing criteria for cell malignancy in benign breast diseases.

OA15 A case series of idiopathic granulomatous mastitis patients and their immunosuppressive management

Abstract Background/Aims Rheumatologists are experts in managing immunosuppression and are asked to supervise immunosuppression for non-rheumatic conditions. Thus, it is important to be aware of these conditions and the regimes required. Idiopathic granulomatosis mastitis (IGM) is a rare inflammatory breast condition which can have systemic manifestations including arthritis. Methods Our index case presented with peripheral ankle synovitis/tenosynovitis, struggling to weight bear, whilst being investigated for a breast mass. Breast US, mammogram and biopsy (acute and chronic inflammatory cells including multi-nucleated giant cells) were completed and there was little response to 3 courses of antibiotics. No mycobacteria were seen on microscopy, ZN stain negative, CXR normal, T spot negative and serum ACE normal. There was no rash and no conditions associated with a seronegative spondyloarthropathy. RF, anti-CCP and ANA were negative. A moderate course of prednisolone immediately resolved the peripheral arthritis, but high-dose steroids were required to reduce the breast mass. The mass recurred upon weaning prednisolone requiring the addition of azathioprine as a steroid-sparing agent. Results Our case series includes the immunosuppressive management of 3 other IGM patients: 1) 43-year-old referred after an 8 year history of alternating breast ‘abscesses’ and sinuses treated with courses of antibiotics to little avail. High dose prednisolone and methotrexate resolved the breast mass within a month. 2) 37-year-old referred with a 14 year history of breast masses and fistulae previously treated with surgery and antibiotics. Currently asymptomatic so commenced on methotrexate. 3) 39-year-old referred with a 3 year history of recurrent sterile breast abscesses previously managed with antibiotics, incision and drainage. Recent small masses had settled with NSAIDs. Conclusion IGM is a rare benign inflammatory breast disease of unknown aetiology, commonest in Middle Eastern populations, median age 30s. The most common presentation is a unilateral painful mass, which can ulcerate, fistulate and form abscesses. Management of IGM varies from expectant/topical steroids/NSAIDs to high dose steroids and DMARDs. A literature review shows that the usual starting dose of prednisolone is 40-60mg; the addition of methotrexate and azathioprine increases likelihood of successful treatment and allows for faster steroid tapering. Surgery for specific types of IGM can also be useful; for example, where there is duct granuloma, surgical excision can be curative. IGM can associate with arthritis, erythema nodosum, and episcleritis. One case series found that 14% of patients with IGM had concomitant arthritis. Key points: In our local experience we have had four patients with IGM, all previously treated with antibiotics or surgical methods but subsequently diagnosed with IGM and referred for immunosuppressive therapy. Being a rare condition, we feel it’s important for clinicians to be aware of IGM and its link with inflammatory arthritis. Disclosure S. Islam: None. P. Stonelake: None. H. John: None.

Associations of Early-Life and Adult Anthropometric Measures with the Expression of Stem Cell Markers CD44, CD24, and ALDH1A1 in Women with Benign Breast Biopsies.

According to the stem cell hypothesis, breast carcinogenesis may be related to the breast stem cell pool size. However, little is known about associations of breast cancer risk factors, such as anthropometric measures, with the expression of stem cell markers in noncancerous breast tissue. The analysis included 414 women with biopsy-confirmed benign breast disease in the Nurses' Health Study and Nurses' Health Study II. Birthweight, weight at age 18, current weight, and current height were reported via self-administered questionnaires. IHC staining of stem cell markers (CD44, CD24, and aldehyde dehydrogenase family 1 member A1) in histopathologically normal epithelial and stromal breast tissue was quantified using an automated computational image analysis system. Linear regression was used to examine the associations of early-life and adult anthropometric measures with log-transformed stem cell marker expression, adjusting for potential confounders. Birthweight [≥10.0 vs. <5.5 lbs: β (95% confidence interval) = 4.29 (1.02, 7.56); P trend = 0.001 in the stroma] and adult height [≥67.0 vs. <63.0 inch: 0.86 (0.14, 1.58); P trend = 0.02 in the epithelium and stroma combined] were positively associated with CD44 expression. Childhood body fatness was inversely associated (P trend = 0.03) whereas adult height was positively associated with CD24 expression in combined stroma and epithelium (P trend = 0.03). Our data suggest that anthropometric measures, such as birthweight, adult height, and childhood body fatness, may be associated with the stem cell expression among women with benign breast disease. Anthropometric measures, such as birthweight, height, and childhood body fatness, may have long-term impacts on stem cell population in the breast.

Validation of prostate and breast cancer detection artificial intelligence algorithms for accurate histopathological diagnosis and grading: a retrospective study with a Japanese cohort

Prostate and breast cancer incidence rates have been on the rise in Japan, emphasising the need for precise histopathological diagnosis to determine patient prognosis and guide treatment decisions. However, existing diagnostic methods face numerous challenges and are susceptible to inconsistencies between observers. To tackle these issues, artificial intelligence (AI) algorithms have been developed to aid in the diagnosis of prostate and breast cancer. This study focuses on validating the performance of two such algorithms, Galen Prostate and Galen Breast, in a Japanese cohort, with a particular focus on the grading accuracy and the ability to differentiate between invasive and non-invasive tumours. The research entailed a retrospective examination of 100 consecutive prostate and 100 consecutive breast biopsy cases obtained from a Japanese institution. Our findings demonstrated that the AI algorithms showed accurate cancer detection, with AUCs of 0.969 and 0.997 for the Galen Prostate and Galen Breast, respectively. The Galen Prostate was able to detect a higher Gleason score in four adenocarcinoma cases and detect a previously unreported cancer. The two algorithms successfully identified relevant pathological features, such as perineural invasions and lymphovascular invasions. Although further improvements are required to accurately differentiate rare cancer subtypes, these findings highlight the potential of these algorithms to enhance the precision and efficiency of prostate and breast cancer diagnosis in Japan. Furthermore, this validation paves the way for broader adoption of these algorithms as decision support tools within the Asian population.