ER Status Research Articles

Association between Radiological and First-Order Statistical Features of the Mammogram, and the Tumor Phenotype in Breast Cancer Patients

Background: Breast cancer is among the most prevalent cancers which can effectively be screened by mammography. The spatial distribution of grey levels of the mammogram known as first-order statistical features (FOSFs) contain higher dimensional data which describe the breast composition. We aim to test these basic measures to differentiate density categories in breast cancer patients, and use them as covariates to investigate the relationship between radiologic and pathologic features of the tumor. Methods: Data from Eighty-five breast cancer subjects, their BI-RADS breast density category (a to d), percentage density (PD), and FOSFs of the mammogram including median, mean, interquartile range, kurtosis, maximum, minimum, standard deviation, skewness, and energy, were extracted. The tumor grade and the percentage of Ki67, ER, PR, and Her2 status were recorded. A linear discriminant analysis, and a support vector machine (SVM) were used to discriminate each density category from others. Then, the relation between variables were investigated using ANCOVA and regression analysis. Results: Density categories a and d were classified by SVM with high accuracy. The key feature of a and d were interquartile range and maximum intensities respectively. Reported tumor margins were related to Her2 overexpression and PR positivity. Spiculated tumor margin predicted percentage of PR expression, with a cumulative odds ratio of 7.85 (CI 2.5- 24.78), when adjusted for age, area of breast, density, and FOSFs, (p=0.0004). Conclusion: The findings of this study suggest that FOSFs can be incorporated in computer-aided systems to adjust for differences in breast composition and to refine risk profiles.

Evaluating Biomarker Dynamics in Breast Cancer Post-Neoadjuvant Chemotherapy: A Retrospective Cross-sectional Study

Background: Neoadjuvant chemotherapy (NACT) is integral to breast cancer management, yet its influence on biomarkers, notably androgen receptor (AR), remains underexplored. This study examines post-NACT alterations in receptor status, including ER, PR AR, HER2 and Ki67 index in breast cancer patients. Methods: A cross-sectional study, spanning three years at a tertiary care center, enrolled patients with invasive breast cancer undergoing mastectomy post-NACT. Pre- and post-NACT specimens underwent histological grading and immunohistochemistry for hormone status, HER2 status, and Ki67 index. Discordance between pre- and post-NACT receptor statuses and expression levels of biomarkers was assessed using McNemar’s and Wilcoxon signed rank tests respectively. Results: Among 100 patients, 35 were assessed. Mean age was 43.83 years, with prevalent T1 tumors (34.3%) and N1 nodal involvement (37.1%). Post-NACT, 54.2% showed no histological grade change. Notable alterations included changes in ER (14.2%), PR (14.2%), and HER2 status (8.57%). AR expression showed a significant change following NACT (p=0.03), while ER expression exhibited a trend towards significance (p=0.06). Ki67 index decreased in only 5.7% of cases. Conclusion: This study unveils intricate biomarker dynamics following NACT in breast cancer, with particular emphasis on AR, hitherto not evaluated. Larger investigations are imperative to elucidate clinical implications and tailor treatment strategies for breast cancer patients undergoing NACT.

Genes Related to Motility in an Ionizing Radiation and Estrogen Breast Cancer Model

Breast cancer is a major global health concern as it is the primary cause of cancer death for women. Environmental radiation exposure and endogenous factors such as hormones increase breast cancer risk, and its development and spread depend on cell motility and migration. The expression of genes associated with cell motility, such as ADAM12, CYR61, FLRT2, SLIT2, VNN1, MYLK, MAP1B, and TUBA1A, was analyzed in an experimental breast cancer model induced by radiation and estrogen. The results showed that TUBA1A, SLIT2, MAP1B, MYLK, and ADAM12 gene expression increased in the irradiated Alpha3 cell line but not in the control or the malignant Tumor2 cell line. Bioinformatic analysis indicated that FLERT2, SLIT2, VNN1, MAP1B, MYLK, and TUBA1A gene expressions were found to be higher in normal tissue than in tumor tissue of breast cancer patients. However, ADAM12 and CYR61 expressions were found to be higher in tumors than in normal tissues, and they had a negative correlation with ESR1 gene expression. Concerning ESR2 gene expression, there was a negative correlation with CYR61, but there was a positive correlation with FLRT2, MYLK, MAP1B, and VNN1. Finally, a decreased survival rate was observed in patients exhibiting high expression levels of TUBA1A and MAP1B. These genes also showed a negative ER status, an important parameter for endocrine therapy. The genes related to motility were affected by ionizing radiation, confirming its role in the initiation process of breast carcinogenesis. In conclusion, the relationship between the patient’s expression of hormone receptors and genes associated with cell motility presents a novel prospect for exploring therapeutic strategies.

Identification Of Risk Factors Of Bone Metastasis Among Iraqi Breast Cancer Women

Background: The most common site of metastases in people with breast cancer is bone metastasis. Patients with advanced phases of cancer are associated with an increased prevalence of several types of metastases, one of which is bone metastasis. Object: Assessment of the risk factors for bone metastases in patients with breast cancer. Patients and Methods: This is a retrospective study of 316 patients with breast cancer who either had bone metastases at the time of diagnosis or developed it later on. The study was carried out between January 2013 and April 2018. Three hundred and sixteen patients were assigned into two groups. In the case group, 100 patients with breast cancer had been diagnosed with bone metastasis by CT, MRI, bone scan, and PET scan; in the control group, there were 216 cases in are control group with breast cancer metastasis to sites other than bone. The questionnaire was created to record all factors (with the exception of demographic information), such as age, histopathological reading for invasive lobular carcinoma, invasive ductal carcinoma, or another type of cancer, ER status, PR status, Her2neu status, lymph node status and stage, and menopausal status. Results: The majority were 45 years of age or younger, and 96.5% of them had invasive ductal carcinoma in terms of hormonal status. Positive ER and PR status is found in 67.7% and 67.1% of the cases, respectively; 40.5% of the cases had amplified Her2neu receptors, 78.5% of the cases had positive lymph nodes, and 41.9% of the cases had (N1) stage. The highest proportion of bone metastasis was associated with negative ER and PR receptors (46.2% and 49%, respectively), while no significant statistical association (P= 0.65). Conclusion: negative ER, PR status, and Her2neu receptors not amplified, lymph node involvement, age 45 and less, infiltrating lobular carcinoma (ILC) histological type, and menopausal state are significant risk factors for bone metastasis in breast cancer.

Differences in Breast Cancer Subtypes among Racial/Ethnic Groups.

Differences in the incidence of breast cancer subtypes among racial/ethnic groups have been evaluated as a contributing factor in disparities seen in breast cancer prognosis. We evaluated new breast cancer cases in Hawai'i to determine if there were subtype differences according to race/ethnicity that may contribute to known disparities. We reviewed 4591 cases of women diagnosed with breast cancer from two large tumor registries between 2015 and 2022. We evaluated breast cancer cases according to age at diagnosis, self-reported race, breast cancer subtype (ER, PR, and HER2 receptor status), histology, county, and year. We found both premenopausal and postmenopausal Native Hawaiian women were less likely to be diagnosed with triple-negative breast cancer (OR = 0.26, 95% CI 0.12-0.58 p = 0.001; OR = 0.54, 95% CI 0.36, 0.80 p = 0.002, respectively). The results of our study support that there are racial/ethnic differences in breast cancer subtypes among our population, which may contribute to differences in outcomes. Further evaluation of clinical and pathological features in each breast cancer subtype may help improve the understanding of outcome disparities seen among different racial/ethnic groups.

120 - The value of T1ρ mapping in preoperatively predicting the status of ER, PR, HER-2 and Ki-67 in breast cancer

120 - The value of T1ρ mapping in preoperatively predicting the status of ER, PR, HER-2 and Ki-67 in breast cancer

The EORTC 22922/10925 trial investigating regional nodal irradiation in stage I-III breast cancer: Outcomes according to locoregional and systemic therapies

The EORTC 22922/10925 trial aimed to investigate the impact on overall survival (OS) of elective internal mammary and medial supraclavicular (IM-MS) radiation therapy (RT) in breast cancer stage I–III. Surgery for the primary tumour and axillary lymph nodes, chest wall RT, boost RT after whole breast RT in breast conserving therapy (BCT), RT to operated axilla, and systemic therapy were per physician’s preference. The aim of the current analysis is to assess breast cancer outcomes according to different locoregional and systemic therapy used in the trial. Material/MethodsData with a median follow-up of 15.7 years were extracted from the trial’s case report forms. Kaplan-Meier curves of disease-free and OS and cumulative incidence curves of breast cancer events were produced. An exploratory analysis of the effect of the type of locoregional and systemic therapy on breast cancer outcomes was conducted using the Cox model or the Fine & Gray model accounting for competing risks, both models being adjusted for baseline patient and disease characteristics and treatment. The significance level was set at 5 %, 2-sided. ResultsOf the 4,004 patients included, 625 (16%) did not receive any postoperative systemic therapy, 1,185 (30%) received endocrine therapy only, 994 (25%) chemotherapy only, and 1,200 (30%) both chemotherapy and endocrine therapy, without differences between the randomisation arms.Administration and type of therapy was associated with age, menopausal status, clinical T- and N-stage and ER status (p < 0.0001). Local control was better with mastectomy (with/without postmastectomy RT) as compared to BCT, but mastectomy was associated with more distant metastasis (DM) as first event. Similarly, DM as first event occurred more in the BCT group that received a boost as compared to no boost and in those who received RT to the lower axillary level. IM-MS RT reduced significantly regional recurrences and improved disease-free survival in a sensitivity stratified analysis. OS was worse with mastectomy as compared to BCT and with irradiation of the axilla but better with sentinel node dissection and adjuvant combined chemo and hormonal therapy. ConclusionDifferent components of therapy influenced the site of first event. IM-MS RT improved outcomes in different breast cancer outcomes were most probably related that the group were balanced due to the trial arms and stratification methods.

Characterization of HER2-Low Breast Tumors among a Cohort of Colombian Women.

HER2-low tumors have shown promise in response to antibody-drug conjugates (ADCs) in recent clinical trials, underscoring the need to characterize this group's clinical phenotype. In this study, we aimed to explore the clinicopathological features, survival rates, and HER2 amplicon mRNA expression of women affected with HER2-low breast cancer, compared with HER2-negative and HER2-positive groups. We included 516 breast cancer patients from Colombia, for whom we compared clinicopathological features, mRNA expression of three HER2 amplicon genes (ERBB2, GRB7 and MIEN1), survival and risk of mortality between HER2-low cases (1+ or 2+ with negative in situ hybridization (ISH) result) with HER2-positive (3+ or 2+ with positive ISH test) and HER2-negative (0+) cases. A higher proportion of patients with better-differentiated tumors and a lower proliferation index were observed for HER2-low tumors compared to the HER2-positive group. Additionally, HER2-low tumors showed higher mRNA expression of the ERBB2 gene and longer overall survival rates compared to HER2-negative cases. Nonetheless, a Cox-adjusted model by ER status and clinical stage showed no statistically significant differences between these groups. Our results show differences in important clinicopathological features between HER2-low and both HER2-positive and negative tumors. Given this unique phenotype, it is crucial to evaluate the potential advantages of ADC therapies for this emerging subtype of breast cancer.

Individualized prediction of non-sentinel lymph node metastasis in Chinese breast cancer patients with ≥ 3 positive sentinel lymph nodes based on machine-learning algorithms

BackgroundAxillary lymph node dissection (ALND) is a standard procedure for early-stage breast cancer (BC) patients with three or more positive sentinel lymph nodes (SLNs). However, ALND can lead to significant postoperative complications without always providing additional clinical benefits. This study aims to develop machine-learning (ML) models to predict non-sentinel lymph node (non-SLN) metastasis in Chinese BC patients with three or more positive SLNs, potentially allowing the omission of ALND.MethodsData from 2217 BC patients who underwent SLN biopsy at Shantou University Medical College were analyzed, with 634 having positive SLNs. Patients were categorized into those with ≤ 2 positive SLNs and those with ≥ 3 positive SLNs. We applied nine ML algorithms to predict non-SLN metastasis. Model performance was evaluated using ROC curves, precision-recall curves, and calibration curves. Decision Curve Analysis (DCA) assessed the clinical utility of the models.ResultsThe RF model showed superior predictive performance, achieving an AUC of 0.987 in the training set and 0.828 in the validation set. Key predictive features included size of positive SLNs, tumor size, number of SLNs, and ER status. In external validation, the RF model achieved an AUC of 0.870, demonstrating robust predictive capabilities.ConclusionThe developed RF model accurately predicts non-SLN metastasis in BC patients with ≥ 3 positive SLNs, suggesting that ALND might be avoided in selected patients by applying additional axillary radiotherapy. This approach could reduce the incidence of postoperative complications and improve patient quality of life. Further validation in prospective clinical trials is warranted.

Genetic evidence supporting potential causal roles of EIF4 family in breast cancer: a two-sample randomized Mendelian study

Translational control plays a crucial role in the regulation of apoptosis, with the EIF4 family serving as one of the mRNA translation factors that modulate the process of mRNA translation based on mRNA characteristics. To address this potential causal role of EIF4 family proteins and breast cancer, Mendelian randomization was employed. The study incorporated four sets of genetics instrumental variables, namely EIF4E, EIF4B, EIF4A, and EIF4EBP2. The outcome variables selected for analysis were the BCAC consortium, which included estrogen receptor positive (ER+) and estrogen receptor negative (ER−) samples. To assess the potential violations of the MR assumption, the primary MR analysis employed inverse variance weighted (IVW), and several sensitivity analyses were conducted. The findings of the two-sample MR analysis indicate that EIF4E has an adverse effect on breast cancer risk (p = 0.028). However, the evidence for the relationship between EIF4E and ER status of breast cancer suggests a weak association with ER+ breast cancer (p = 0.054), but not with ER- breast cancer (p > 0.05). The study findings indicate that EIF4A is not causally linked to the risk of ER+ breast cancer, but is significantly associated with an elevated risk of ER− breast cancer (p = 0.028). However, the evidence is inadequate to support the effects of EIF4B and EIF4EBP2 on breast cancer (p > 0.05). Our results suggest that EIF4 may be a potential factor in the occurrence and development of breast cancer, which may lead to a better understanding of its causes and prevention.

Postoperative radiotherapy in women with early operable breast cancer (Scottish Breast Conservation Trial): 30-year update of a randomised, controlled, phase 3 trial

Breast-conserving surgery, adjuvant systemic therapy, and radiotherapy are the standard of care for most women with early breast cancer. There are few reports of clinical outcomes beyond the first decade of follow-up of randomised trials comparing breast-conserving surgery with or without radiotherapy. We present a 30-year update of the Scottish Breast Conservation Trial. In this randomised, controlled, phase 3 trial across 14 hospitals in Scotland, women aged younger than 70 years with early breast cancer (tumours ≤4 cm [T1 or T2 and N0 or N1]) were included. They underwent breast-conserving surgery (1 cm margin) with axillary node sampling or clearance. Oestrogen receptor (ER)-rich patients (≥20 fmol/mg protein) received 20 mg oral tamoxifen daily for 5 years. ER-poor patients (<20 fmol/mg protein) received chemotherapy (cyclophosphamide 600 mg/m2, methotrexate 50 mg/m2, and fluorouracil 600 mg/m2 every 21 days intravenously in eight courses). Stratification was by menstrual status (within or more than 12 months from last menstrual period) and ER status (oestrogen concentration ≥20 fmol/mg protein, <20 fmol/mg protein, or unknown) and patients were randomly assigned (1:1) to high-dose (50 Gy in 20-25 fractions) local or locoregional radiotherapy versus no radiotherapy. No blinding was possible due to the nature of the treatment. We report the primary endpoint of the original trial, ipsilateral breast tumour recurrence, and the co-primary endpoint, overall survival. Clinical outcomes were compared by the log-rank test. Hazard ratios (HRs) are reported, with no radiotherapy as the reference group. Failures of the proportional hazards assumption are reported if significant. All analyses are by intention to treat. Between April 1, 1985, and Oct 2, 1991, 589 patients were enrolled and randomly assigned to the two treatment groups (293 to radiotherapy and 296 to no radiotherapy). After exclusion of four ineligible patients (two in each group), there were 291 patients in the radiotherapy group and 294 patients in the no radiotherapy group. Median follow-up was 17·5 years (IQR 8·4-27·9). Ipsilateral breast tumour recurrence was significantly lower in the radiotherapy group than in the no radiotherapy group (46 [16%] of 291 vs 107 [36%] of 294; HR 0·39 [95% CI 0·28-0·55], p<0·0001). Although there were differences in the hazard rate for ipsilateral breast tumour recurrence in the first decade after treatment (HR 0·24 [95% CI 0·15-0·38], p<0·0001), subsequent risks of ipsilateral breast tumour recurrence were similar in both groups (0·98 [0·54-1·79], p=0·95). There was no difference in overall survival between the two groups (median 18·7 years [95% CI 16·5-21·5] in the no radiotherapy group vs 19·2 years [16·9-21·3] in the radiotherapy group; HR 1·08 [95% CI 0·89-1 ·30], log-rank p=0·43). Our findings suggest that patients whose biology predicts a late relapse a decade or more after breast-conserving surgery for early breast cancer might gain little from adjuvant radiotherapy. Breast Cancer Institute (part of Edinburgh and Lothian Health Foundation) and PFS Genomics (now part of Exact Sciences).

Association analysis of miRNA-146a and miRNA-196a polymorphism with breast cancer risk in Khyber Pakhtunkhwa, Pakistan: a preliminary study.

microRNAs (miRNAs) are small, noncoding RNA molecules, functioning either as oncogenes or tumor suppressor genes. SNPs in miRNAs might modify the expression of genes associated with miRNAs, enhancing susceptibility to breast cancer. Both miRNA-146a (rs2910164) and miRNA-196a (rs11614913) are identified and significantly associated with breast cancer risk in several ethnicities, but remains unexplored in Khyber Pakhtunkhwa population of Pakistan. This study was aimed to check the relation of selected SNPs with breast cancer risk. The research cohort included 100 breast cancer patients and 100 healthy controls. All the participants were subjected for DNA extraction followed by T-ARMS PCR and gel electrophoresis. The results revealed a strong association between risk allele (G) of miRNA-146a and increased risk of breast cancer (OR = 2.04, P = 0.0006). Similarly, heterozygous and mutant genotypes also indicated high risk and significant association with breast cancer risk (CG; OR = 0.51, 9 P = 0.0001) (GG; OR = 3.76, P = 0.04). However, risk allele (T) of miRNA-196a (rs11614913) failed to exhibit significant association with breast cancer risk (OR = 0.92 P = 0.68). Similarly, the heterozygous and mutant genotype did not show significant association with breast cancer risk (CT; OR = 0.52, P = 0.125 (TT; OR = 0.88, P = 0.84). Furthermore, miRNA-146a (rs2910164) and miRNA-196a (rs11614913) polymorphisms exhibited non-significant associations with family history (P = 0.34, P = 0.77), PR status (P = 0.310, P = 0.397), ER status (P = 0.992, P = 0.981), nodal status (P = 0.86, P = 0.90), and menstrual status (P = 0.97, P = 0.09). Notably, miRNA-196a showed a significant association with the metastasis group (P = 0.010) and cancer stages (P = 0.047). In conclusion, this study highlights the association of miRNA-146a (rs2910164) polymorphism with breast cancer risk but suggested non-significant association of miRNA-196a (rs11614913) with breast cancer risk. However, these findings need to be confirmed through larger data set for more accurate result.

Pathological Changes Following Neoadjuvant Endocrine Therapy (NAET): A Multicentre Study of 391 Breast Cancers.

Oestrogen receptor (ER)-positive breast cancer (BC) is generally well responsive to endocrine therapy. Neoadjuvant endocrine therapy (NAET) is increasingly being used for downstaging ER-positive tumours. This study aims to analyse the effect of NAET on a well-characterised cohort of ER-positive BC with particular emphasis on receptor expression. This is a retrospective United Kingdom (UK) multicentre study of 391 patients who received NAET between October 2012 and October 2020. Detailed analyses of the paired pre- and post-NAET morphological changes and hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) expression were performed. The median duration of NAET was 86 days, with median survival and overall survival rates of 380 days and 93.4%, respectively. A total of 90.3% of cases achieved a pathological partial response, with a significantly higher rate of response in the HER2-low cancers. Following NAET, BC displayed some pathological changes involving the tumour stroma including central scarring and an increase in tumour infiltrating lymphocytes (TILs) and tumour cell morphology. Significant changes associated with the duration of NAET were observed in tumour grade (30.6% of cases), with downgrading identified in 19.3% of tumours (p < 0.001). The conversion of ER status from positive to low or negative was insignificant. The conversion of progesterone receptor (PR) and HER2 status to negative status was observed in 31.3% and 38.1% of cases, respectively (p < 0.001). HER2-low breast cancer decreased from 63% to 37% following NAET in the paired samples. Significant morphological and biomarker changes involving PR and HER2 expression occurred following NAET. The findings support biomarker testing on pre-treatment core biopsies and post-treatment residual carcinoma.

The diagnostic performance of T1 mapping in the assessment of breast lesions: A preliminary study

PurposeTo assess T1 mapping performance in distinguishing between benign and malignant breast lesions and to explore its correlation with histopathologic features in breast cancer. MethodsThis study prospectively enrolled 103 participants with a total of 108 lesions, including 25 benign and 83 malignant lesions. T1 mapping, diffusion-weighted imaging (DWI), and dynamic contrast-enhanced (DCE) were performed. Two radiologists independently outlined the ROIs and analyzed T1 and apparent diffusion coefficient (ADC) values for each lesion, assessing interobserver reliability with the intraclass correlation coefficient (ICC). T1 and ADC values were compared between benign and malignant lesions, across different histopathological characteristics (histological grades, estrogen, progesterone and HER2 receptors expression, Ki67, N status). Receiver operating characteristic (ROC) analysis and Pearson correlation coefficient (ρ) were performed. ResultsT1 values showed statistically significant differences between benign and malignant groups (P < 0.001), with higher values in the malignant (1817.08 ms ± 126.64) compared to the benign group (1429.31 ms ± 167.66). In addition, T1 values significantly increased in the ER (−) group (P = 0.001). No significant differences were found in T1 values among HER2, Ki67, N status, and histological grades groups. Furthermore, T1 values exhibited a significant correlation (ρ) with ER (P < 0.01) and PR (P = 0.03). The AUC for T1 value in distinguishing benign from malignant lesions was 0.69 (95 % CI: 0.55 – 0.82, P = 0.005), and for evaluating ER status, it was 0.75 (95 % CI: 0.62 – 0.87, P = 0.002). ConclusionsT1 mapping holds the potential as an imaging biomarker to assist in the discrimination of benign and malignant breast lesions and assessing the ER expression status in breast cancer.

Significance of Multi-Cancer Genome Profiling Testing for Breast Cancer: A Retrospective Analysis of 3326 Cases from Japan's National Database.

Background: Breast cancer (BC) has the highest morbidity rate and the second-highest mortality rate of all cancers among women. Recently, multi-cancer genome profiling (multi-CGP) tests have become clinically available. In this study, we aimed to clarify the significance of multi-CGP testing of BC by using the large clinical dataset from The Center for Cancer Genomics and Advanced Therapeutics (C-CAT) profiling database in Japan. Materials and Methods: A total of 3744 BC cases were extracted from the C-CAT database, which enrolled 60,250 patients between June 2019 and October 2023. Of the 3744 BC cases, a total of 3326 cases for which the C-CAT included information on ER, PR, and HER2 status were classified into four subtypes, including TNBC, HR+/HER2-, HR+/HER2+, and HR-/HER2+. Comparisons between groups were performed by the χ2 test or Fisher's exact test using EZR. Kaplan-Meier curves were created using the log-rank test. Results: Of all 3326 cases analyzed, 1114 (33.5%) were TNBC cases, HR+/HER2- accounted for 1787 cases (53.7%), HR+/HER2+ for 260 cases (7.8%), and HR-/HER2+ for 165 cases (5.0%). Genetic abnormalities were most frequently detected in TP53 (58.0%), PIK3CA (35.5%), MYC (18.7%), FGF19 (15.5%), and GATA3 (15.1%) across all BCs. The rate of TMB-High was 12.3%, and the rate of MSI-High was 0.3%, in all BC cases. Therapeutic drugs were proposed for patients with mutations in six genes: PIK3CA, ERBB2, PTEN, FGFR1, ESR1, and AKT1. The prognoses of HR+/HER2- cases were significantly (p = 0.044) better in the treated group than in the untreated group. Conclusions: These findings suggest that cancer gene panel testing is useful for HR+/HER2- cases.

Biomarker conversion from primary breast cancer to synchronous axillary lymph node metastasis and neoadjuvant therapy response: a single-center analysis

PurposeThe biomarker characteristics of breast cancer plays an important role in predicting treatment sensitivity. The aim of the present study was to compare immunohistochemical profiles (ER, PR, HER2, and Ki67) between the primary tumor and synchronous axillary lymph node metastasis and investigate the subsequent effects on neoadjuvant therapy response.MethodsA total of 358 patients with pathologically confirmed synchronous axillary lymph node metastasis at first diagnosis and treated by neoadjuvant therapy at Peking University First Hospital from January 1, 2013 to December 31, 2022 were included in this retrospective study. Clinicopathologic data, especially receptor status in primary and metastatic foci, was collected for each case.ResultsChange of ER, PR, HER2, and Ki67 expression was observed in 5.9%, 8.7%, 12.6%, and 17.3% of patients, respectively. HR discordance was observed more frequently when the ER status (p = 0.023) or PR status (p = 0.010) of primary tumor was negative, while HER2 discordance seemed to be more frequent when the HER2 status of primary tumor was HER2-0 or HER2-low (p < 0.001). Patients with loss of HR-positivity (positive to negative) responded to neoadjuvant chemotherapy better compared to those with stable positive HR expression (50% vs. 11.1%, p = 0.0017). A significantly decrease in pCR rate was observed in patients with unstable HER2 status, but not in the HER2-0/HER2-low subgroup.ConclusionReceptor discordance between primary tumor and synchronous axillary LNM appears to already exist before any anti-tumor therapy. This instability has limited clinical impact on the choice of neoadjuvant therapy at current stage, but further investigation is warranted with the incremental application of endocrine drugs and ADCs in neoadjuvant therapy.

Association between stromal tumor-infiltrating lymphocytes (TILs) and pathologic complete response (pCR) in patients with early breast cancer (BC) treated with neoadjuvant chemotherapy and HER2-directed therapies in NSABP B-41.

3017 Background: In the phase 3 NSABP B-41 trial, there was an association between pCR and survival in 519 women with early HER2-positive BC treated with neoadjuvant chemotherapy in combination with trastuzumab (T), lapatinib (L), or both (TL). There is a need to identify prognostic biomarkers to tailor patients’ treatment, and the quantification of stromal TILs represents a promising, accessible, and reproducible option. In this analysis, we studied the association between TILs and pCR. Methods: Eligible patients had a baseline core biopsy sample, known pCR status, and no consent withdrawal for the use of specimens. Slides were scanned using an Aperio GT 450 automated scanner to create whole slide images. TIL analysis was then completed based on the international TIL working group guidelines (RS). Patients were grouped into three TIL score categories based on tumor TIL %: low (1-5%), intermediate (6-30%), and high (31-95%). The dose-response relationship between TIL percentage and pCR was explored via generalized linear models with splines. Results: 257 patients were included. 89 (35%) received T, 92 (36%) L, and 76 (29%) TL. 149 (58%) had ER-positive BC. TIL categories in this cohort: 49% low, 22% intermediate, and 29% high. TIL expression was similar across BC intrinsic subtypes and by ER. There was no association between the TIL group and pCR, irrespective of the treatment group (p=0.98). Among tumors with low TILs, T or TL had similar pCR compared to L alone (51.3 v 49%; p=0.95). Among tumors with high TILs, T or TL had higher pCR than L (61.2 v 40.4%; p=0.04). Among patients with ER-positive BC, high TILs were associated with a numerical increase in pCR rate (56% vs 39.6%; p=0.11). Among patients with ER-negative tumors, high TILs were associated with a numerical decreased rate of pCR (50% v. 66.7%; p=0.15). The p-value of the Breslow test of homogeneity of the odds ratios across ER status was 0.016, suggesting that the association between TILs (0-30 v. &gt;30) and pCR varies across ER status.No interaction between the TIL percentage and age, nodal status, menopausal status, or histologic grade was noted. Conclusions: This analysis revealed that patients with a high TIL percentage treated with T or TL compared to L were more likely to achieve a pCR. These findings can be partially explained by the mechanism of action of the HER2-directed agents. T leads to antibody-dependent cell-mediated cytotoxicity, and a higher percentage of TILs may enhance this mechanism, whereas L has intracellular tyrosine kinase disruption. The association between TILs and pCR varied across ER status. Our next steps include additional studies assessing the interaction between TILs and long-term outcomes, as well as gene expression and TILs to validate this biomarker for future clinical trials in HER2+ early BC. Clinical trial information: NCT00486668 .

A blind validation of a deep-learning solution providing HER2, ER, and PR results from H&amp;E-stained breast cancer specimens.

562 Background: Newly diagnosed breast cancer specimens are routinely tested for oestrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2) status. This requires additional immunohistochemistry (IHC) +/- in situ hybridisation (ISH) assessment. This can increase laboratory/pathologist workloads and turnaround times. A computer-based approach could help to alleviate these issues. PANProfiler Breast is a deep-learning solution designed to predict ER/PR status and detect HER2 negative cases from whole slide images (WSIs) of haematoxylin and eosin (H&amp;E)-stained breast cancer tissue. Here we present a blind validation of PANProfiler Breast. Methods: Three cohorts of H&amp;E-stained archival breast cancers (400 cases, 692 WSIs) from St James’s University Hospital, Leeds, UK, were assigned for calibration (200 cases, 344 WSIs) and blind validation (200 cases, 348 WSIs). Slides were scanned at 40x magnification on an Aperio GT450 (Leica, Illinois, USA) scanner. PANProfiler returned “Positive”, “Negative” or “Indeterminate” for ER and PR, and “Negative” or “Indeterminate” for HER2. Results were compared to the ER/PR/HER2 status given in the corresponding pathology report. For calibration and blind validation, the WSI(s) corresponding to the IHC/ISH testing block was used for analysis. One case with missing HER2 status was excluded from HER2 analyses. Confusion matrices enabled analysis of concordance. While a conventional Positive/Negative confusion matrix was used for ER/PR, “Negative” results were used as the reference Positive event for HER2. Results: Case concordance for ER and PR status across the three cohorts ranged from 89.74-92.86% and 85.71-90.91% respectively. Additionally, sensitivity for ER ranged from 89.19-100%, with specificity ranging between 62.50-100%. For PR, sensitivity was between 87.50% and 93.48% and specificity between 75.00% and 83.33%. False negative rates for both ER and PR were between 0-10.81% and 6.52-12.50% respectively. Regarding HER2, sensitivity was relatively low, ranging between 30.77% and 37.04%. However, over 90% concordance was seen across all cohorts for cases PANProfiler predicted as HER2 “Negative”. Specificity and positive predictive value were also over 90% throughout the three cohorts. Additionally, false positive rates were 0.00%, 4.35% and 9.52% for HER2 across these same three cohorts. Test replacement rates varied amongst the cohorts with 70-84% for ER, 55-84% for PR and 22-27% for HER2. Conclusions: This blind validation of PANProfiler Breast shows impressive levels of performance for predicting ER and PR status in breast cancer WSIs. For HER2, the technology demonstrated a striking level of confidence for cases predicted as HER2 “Negative”. Further development and analysis are warranted to increase the number of HER2 negative BC WSIs that PANProfiler is able to identify.

Multiomic factor analysis for pathologic complete response (pCR) after 12 weeks of pembrolizumab + trastuzumab + pertuzumab in HER2-enriched (HER2-E) early breast cancer (eBC) in the Keyriched-1 trial.

590 Background: pCR successfully identified candidates for (chemotherapy) de-escalation in the ADAPT HER2+ trial program. Here, we report biomarker analysis for pCR in the single arm, hypothesis-generating Keyriched-1 trial (NCT03988036) in HER2-E eBC treated with pembrolizumab and dual HER2 blockade. The trial rationale is based on high efficacy of anti-HER2 agents and potentially high immunogenicity and immune checkpoint protein expression in HER2-E eBC. Methods: 48 patients with HER2 2+ (ISH+) or 3+ eBC (stage I-III) and HER2-E subtype received pembrolizumab (200 mg), trastuzumab biosimilar (loading dose, LD 8 mg/kg, maintenance dose, MD 6 mg/kg), and pertuzumab (LD 840 mg/kg, MD 420 mg/kg) q3w for 12 weeks. Primary outcome was pCR (ypT0/is ypN0). Multiomic factor analysis was performed using different combinations of biomarker datasets: baseline BC360 single genes and gene signatures, multiplexed immunohistochemistry (mIHC), stromal tumor infiltrating lymphocytes (sTILs), somatic mutations and tumor mutational burden, and changes in circulating tumor DNA status under therapy. Factors representing combined markers developed from these pooled datasets were identified based on eigenvalue &gt;1 criteria. Logistic regression with factors dichotomized by median score was conducted to analyze their association with pCR. Furthermore, logistic regression with elastic net regularization was performed using all single markers, factors from multiomic factor analysis, and clinical characteristics. Results: Factor involving gene expression (mainly related to immune response and tumorigenesis), mIHC markers (immune and HER2) in stroma, and sTILs datasets was significantly associated with pCR. Using the median as cutoff, higher scores increased the odds of pCR (unadj. OR 5.00, 95%CI 1.35, 18.56; p=.016). pCR rates were 66.7% and 28.6% in the high and low score groups, respectively. Effect of the factor (high vs low; OR 2.19) was also important in a model that additionally included clinical markers: grade (3 vs 2; OR 2.57), ER status (ER+ vs ER-; OR 0.89), cT (cT 2/3 vs 1; OR 0.69), cN (cN 1/2 vs 0; OR 0.51), and PR status (PR+ vs PR-; OR 0.34). When standardized values for all individual markers from gene expression, mIHC, and sTIL datasets were analyzed, markers with greatest impact on pCR vs. non-pCR were genes FNBP1, CD36, MYCN, and SIX1 (OR 1.43-1.62) and PR status (OR 0.65), with stronger impact than grade (OR 1.22) or nodal status (OR 0.90). Conclusions: Our multiomic analysis uncovered potential biomarkers for pCR in HER2-E eBC treated with immune therapy and dual-HER2 blockade alone. These results together with the results from the ADAPT translational research program support validation in larger trials investigating chemotherapy-free regimens in selected patients with HER2+ eBC. Clinical trial information: NCT03988036 .

Immune checkpoint inhibition for the treatment of metastatic breast cancer with high tumor mutational burden: Real world clinical and genomic correlates of response.

1078 Background: Pembrolizumab has received tumor-agnostic approval for the treatment of unresectable/metastatic solid tumors carrying a tumor mutational burden (TMB) &gt;10 mut/Mb. The registrational KEYNOTE-158 study, however, did not include any patients with metastatic breast cancer (MBC). Here we present a retrospective study of patients with TMB-high MBC treated with immune checkpoint inhibition (ICI) and report real-world efficacy endpoints, including progression free survival as well as clinical and genomic characteristics that may be associated with duration of response. Methods: All patients with MBC treated with an ICI at MSK and with TMB-high tumors (&gt;10 mut/Mb) assessed by tumor-normal targeted sequencing (MSK-IMPACT) were included. Clinicopathological and demographic data were obtained via the MSK Breast Cancer Translational Program. Mutational signatures were determined using the Signature Multivariate Analysis (SigMA) algorithm. Real world progression free survival (PFS) was determined clinically and analyzed using Kaplan-Meier estimates. Univariate and multivariate analyses were performed using Cox-proportional hazards models. Results: Of 688 patients with TMB-high breast cancer at MSKCC, 87 had received ICI-based therapy for estrogen receptor positive (ER+), triple negative breast cancer (TNBC), and HER2+ MBC. Of those, 45 patients were treated with ICI monotherapy (29 ER+, 11 TNBC, 5 HER2), 31 were treated with ICI + chemotherapy (12 ER+, 19 TNBC), and 11 were treated with combinations of ICI and targeted therapy (8 ER+, 1 TNBC, 2 HER2). Median age at time of ICI treatment across all patients was 60. ICI was the median 5th line therapy for all patients (range 1-16). Median PFS of ICI for all patients was 3.17 months (95%CI 2.27-5.5). Multivariable analysis did not show statistically significant differences in PFS based upon treatment regimen (monotherapy vs. chemoIO HR 1.03, 95%CI 0.54-1.96, p= 0.92, monotherapy vs combination IO HR 1.66, 95%CI 0.69-4.02, p=0.26), ER status (ER- vs ER+, HR 1.20, 95%CI 0.63-2.28, p=0.57), or HER2 status (HER2- vs HER2+, HR 1.63, 95%CI 0.51-5.20, p=0.41. However, longer PFS was significantly associated with TMB&gt;30 (HR 0.35, 95%CI 0.13-0.92, p=0.03) and dominant APOBEC signature score (APOBEC- vs APOBEC+, HR 0.49, 95%CI 0.25-0.98, p=0.04). Shorter PFS was significantly associated with later treatment line at the time of ICI exposure (continuous, HR 1.22, 95%CI 1.11-1.36, p=0.0001). Conclusions: In this heavily pretreated real-world cohort, ICI in TMB high MBC shows modest clinical activity. Our analysis suggests that ICI may be more effective in MBC patients that are less heavily pre-treated, have TMB&gt;30, and have a predominantly APOBEC mutational signature. Further translational work is necessary to explore the mechanisms of these findings.