HER2-negative Breast Cancer Research Articles

Outcomes in Nonmetastatic Hormone Receptor-Positive HER2-Negative Pure Mucinous Breast Cancer: A Multicenter Cohort Study.

Although considered a favorable subtype, pure mucinous breast cancer (PMBC) can recur, and evidence for adjuvant therapy is limited. We aimed to compare outcomes of nonmetastatic PMBC with invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) to address these uncertainties. Individual patient-level data from 6 centers on stage I-III hormone receptor-positive and HER2-negative PMBC, IDC, and ILC were used to analyze recurrence-free interval (RFI), recurrence-free survival (RFS), and overall survival (OS), and to identify prognostic factors for PMBC. Data from 20,684 IDC cases, 1,475 ILC cases, and 943 PMBC cases were used. Median follow-up was 6.6 years. Five-year RFI, RFS, and OS for PMBC were 96.1%, 94.9%, and 98.1%, respectively. On multivariable Cox regression, PMBC demonstrated superior RFI (hazard ratio [HR], 0.59; 95% CI, 0.43-0.80), RFS (HR, 0.70; 95% CI, 0.56-0.89), and OS (HR, 0.71; 95% CI, 0.53-0.96) compared with IDC. ILC showed comparable outcomes to IDC. Fewer than half (48.7%) of recurrences in PMBC were distant, which was a lower rate than for IDC (67.3%) and ILC (80.6%). In contrast to RFI, RFS events were driven more by non-breast cancer deaths in older patients. Significant prognostic factors for RFI among PMBC included positive lymph node(s) (HR, 2.42; 95% CI, 1.08-5.40), radiotherapy (HR, 0.44; 95% CI, 0.23-0.85), and endocrine therapy (HR, 0.25; 95% CI, 0.09-0.70). No differential chemotherapy associations with outcomes were detected across PMBC subgroups by nodal stage, tumor size, and age. A separate SEER database analysis also did not find any association of improved survival with adjuvant chemotherapy in these subgroups. Compared with IDC, PMBC demonstrated superior RFI, RFS, and OS. Lymph node negativity, adjuvant radiotherapy, and endocrine therapy were associated with superior RFI. Adjuvant chemotherapy was not associated with better outcomes.

The emerging predictive and prognostic role of HER2 in HER2-negative early breast cancer: a retrospective study.

Many patients with early breast cancer (eBC) undergoing neoadjuvant chemotherapy do not achieve pathological complete response (pCR), which is a prognostic factor. We examined the role of HER2-low expression in predicting pCR and prognosis in HER2-negative eBC. We evaluated patients with stage I-III HER2-negative BC, treated between 2013 and 2023 at The Royal Marsden NHS Foundation Trust, London. Tumors were classified based on estrogen receptor (ER) status and into HER2-low and HER2-zero subgroups. We analyzed pCR rates, relapse-free survival (RFS) and overall survival (OS). 754 patients were included in the analysis. pCR rate was 8.9% in the ER+ /HER2-low, 16.5% in the ER+ /HER2-zero, 38.9% in the ER- ER-/HER2-low and 35.9% in the ER-/HER2-zero eBC (p < 0.001). Multivariable analysis showed a significantly lower pCR rate in HER2-low compared to HER2-zero BC in the ER+ subgroup. At a median follow-up of 63.8months (59.9-67.4), we observed longer OS in HER2-low compared to HER2-zero patients in the overall and in the ER+ population. There was no predictive or prognostic impact of HER2-low status in the ER- population. This study supports the interpretation of HER2 status as a possible prognostic and predictive biomarker for HER2-negative eBC, especially among patients with ER+ disease.

Reinforcement learning (RL)-based semantic segmentation and attention based backpropagation convolutional neural network (ABB-CNN) for breast cancer identification and classification using mammogram images

Reinforcement learning (RL)-based semantic segmentation and attention based backpropagation convolutional neural network (ABB-CNN) for breast cancer identification and classification using mammogram images

Next generation selective estrogen receptor degraders in postmenopausal women with advanced-stage hormone receptors-positive, HER2-negative breast cancer

Breast cancer is the most prevalent malignancy in women, and is characterized by its heterogeneity; exhibiting various subgroups identifiable through molecular biomarkers that also serve as predictive indicators. More than two thirds of breast tumors are classified as luminal with positive hormone receptors (HR), indicating that cancer cells proliferation is promoted by hormones. Endocrine therapies play a vital role in the effective treatment of breast cancer by manipulating the signaling of estrogen receptors (ER), leading to a reduction in cell proliferation and growth rate. Selective estrogen receptor modulators (SERMs), such as tamoxifen and toremifene, function by blocking estrogen’s effects. Aromatase inhibitors (AI), including anastrozole, letrozole and exemestane, suppress estrogen production. On the other hand, selective estrogen receptor degraders (SERDs), like fulvestrant, act by blocking and damaging estrogen receptors. Tamoxifen and AI are widely used both in early- and advanced-stage disease, while fulvestrant is used as a single agent or in combination with other agents like the cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors (palbociclib, abemaciclib, ribociclib) or alpelisib for advanced-stage disease. Currently, SERDs are recognized as an effective therapeutic approach for the treatment of ER-positive breast cancer, showing proficiency in reducing and blocking ER signaling. This review aims to outline the ongoing development of novel oral SERDs from a practical therapeutic perspective, enhancing our understanding of the mechanisms of action underlying these compounds.

Breast cancer diagnosis using support vector machine optimized by improved quantum inspired grey wolf optimization

A prompt diagnosis of breast cancer in its earliest phases is necessary for effective treatment. While Computer-Aided Diagnosis systems play a crucial role in automated mammography image processing, interpretation, grading, and early detection of breast cancer, existing approaches face limitations in achieving optimal accuracy. This study addresses these limitations by hybridizing the improved quantum-inspired binary Grey Wolf Optimizer with the Support Vector Machines Radial Basis Function Kernel. This hybrid approach aims to enhance the accuracy of breast cancer classification by determining the optimal Support Vector Machine parameters. The motivation for this hybridization lies in the need for improved classification performance compared to existing optimizers such as Particle Swarm Optimization and Genetic Algorithm. Evaluate the efficacy of the proposed IQI-BGWO-SVM approach on the MIAS dataset, considering various metric parameters, including accuracy, sensitivity, and specificity. Furthermore, the application of IQI-BGWO-SVM for feature selection will be explored, and the results will be compared. Experimental findings demonstrate that the suggested IQI-BGWO-SVM technique outperforms state-of-the-art classification methods on the MIAS dataset, with a resulting mean accuracy, sensitivity, and specificity of 99.25%, 98.96%, and 100%, respectively, using a tenfold cross-validation datasets partition.

Application of machine learning in the analysis of multiparametric MRI data for the differentiation of treatment responses in breast cancer: retrospective study.

The objective of this study is to develop and validate a multiparametric MRI model employing machine learning to predict the effectiveness of treatment and the stage of breast cancer. The study encompassed 400 female patients diagnosed with breast cancer, with 200 individuals allocated to both the control and experimental groups, undergoing examinations in Shenzhen, China, during the period 2017-2023. This study pertains to retrospective research. Multiparametric MRI was employed to extract data concerning tumor size, blood flow, and metabolism. The model achieved high accuracy, predicting treatment outcomes with an accuracy of 92%, sensitivity of 88%, and specificity of 95%. The model effectively classified breast cancer stages: stage I, 38% (P = 0.027); stage II, 72% (P = 0.014); stage III, 50% (P = 0.032); and stage IV, 45% (P = 0.041). The developed model, utilizing multiparametric MRI and machine learning, exhibits high accuracy in predicting the effectiveness of treatment and breast cancer staging. These findings affirm the model's potential to enhance treatment strategies and personalize approaches for patients diagnosed with breast cancer. Our study presents an innovative approach to the diagnosis and treatment of breast cancer, integrating MRI data with machine learning algorithms. We demonstrate that the developed model exhibits high accuracy in predicting treatment efficacy and differentiating cancer stages. This underscores the importance of utilizing MRI and machine learning algorithms to enhance the diagnosis and individualization of treatment for this disease.

Long-term prospective outcome data using EndoPredict as risk stratification and chemotherapy decision biomarker in hormone receptor-positive, HER2-negative early breast cancer

Abstract Purpose To report the prospective long-term outcome data of patients whose chemotherapy decision was guided by the EndoPredict test. Methods Patients with hormone receptor-positive HER2-negative early breast cancer with 0–3 positive lymph nodes were enrolled. The EndoPredict test was carried out on all tumor samples. Treatment compliance, local recurrence, distant metastases, and survival were evaluated. Associations of EPclin risk stratification with 5-year disease-free survival and distant metastasis-free survival were evaluated by time-to-event analysis. Results 368 consecutive patients were included in the analysis. Median follow-up was 8.2 years. EndoPredict allocated 238 (65%) in the low-risk and 130 (35%) patients in the high-risk group. Risk for disease recurrence or death in EPclin high-risk patients was twofold higher than in EPclin low-risk patients (hazard ratio [HR] 2.08; 95% CI 1.26–3.44; p = 0.004). EPclin low-risk patients had a 5-year disease-free survival of 95.3% (95% CI 92.6–98.0%). EPclin high-risk patients were at higher risk of developing distant metastases or death (HR 2.21; 95% CI 1.27–3.88; p = 0.005). EPclin high-risk patients who underwent chemotherapy had a 5-year DFS of 89.1% (95% CI 82.7–96.1%) in contrast to high-risk patients without chemotherapy (68.9%; 95% CI 56.2–84.5%; HR 0.46; 95% CI 0.23–0.95; p = 0.036). EPclin high-risk patients were at higher risk of experiencing distant metastases or death than EPclin low-risk patients regardless of menopausal status (premenopausal: HR 3.55; 95% CI 1.17–12.32; p = 0.025; postmenopausal: HR 1.92; 95% CI 0.99–3.7; p = 0.054). Conclusion EndoPredict can guide decisions on adjuvant chemotherapy in early luminal breast cancer. EndoPredict risk stratification is also applicable in premenopausal women.

Membership Weight Salp Swarm Algorithm (MWSSA) based feature selection and deep learning approach for breast cancer classification of SNP genomics data

Membership Weight Salp Swarm Algorithm (MWSSA) based feature selection and deep learning approach for breast cancer classification of SNP genomics data

Do proton pump inhibitors affect the effectiveness of cyclin-dependent kinase 4/6 inhibitors in advanced HR positive, HER2 negative breast cancer? A meta-analysis

Graphical Abstract

Pseudo-class part prototype networks for interpretable breast cancer classification

Interpretability in machine learning has become increasingly important as machine learning is being used in more and more applications, including those with high-stakes consequences such as healthcare where Interpretability has been regarded as a key to the successful adoption of machine learning models. However, using confounding/irrelevant information in making predictions by deep learning models, even the interpretable ones, poses critical challenges to their clinical acceptance. That has recently drawn researchers’ attention to issues beyond the mere interpretation of deep learning models. In this paper, we first investigate application of an inherently interpretable prototype-based architecture, known as ProtoPNet, for breast cancer classification in digital pathology and highlight its shortcomings in this application. Then, we propose a new method that uses more medically relevant information and makes more accurate and interpretable predictions. Our method leverages the clustering concept and implicitly increases the number of classes in the training dataset. The proposed method learns more relevant prototypes without any pixel-level annotated data. To have a more holistic assessment, in addition to classification accuracy, we define a new metric for assessing the degree of interpretability based on the comments of a group of skilled pathologists. Experimental results on the BreakHis dataset show that the proposed method effectively improves the classification accuracy and interpretability by respectively 8%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$8 \\%$$\\end{document} and 18%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$18 \\%$$\\end{document}. Therefore, the proposed method can be seen as a step toward implementing interpretable deep learning models for the detection of breast cancer using histopathology images.

Incidence and survival of primary metastatic breast cancer in Denmark; implication of breast cancer screening, classification, and staging practice.

Primary metastatic breast cancer (pMBC) accounts for 5-10% of annual breast cancers with a median survival of 3-4 years, varying among subtypes. In Denmark, the incidence of breast cancer increased until 2010, followed by a stabilisation. Several factors influencing pMBC incidence and survival, including screening prevalence, staging methods, and classification standards, remain pivotal but inadequately documented. This retrospective observational study involving pMBC patients diagnosed between 2000 and 2020 encompassed all Danish oncology departments. Data from the Danish Breast Cancer Group database and the National Patient Register included diagnosis specifics, demographics, treatment, and follow-up. Between 2000 and 2020, 3,272 patients were diagnosed with pMBC, a rise from 355 patients in 2000-2004 to 1,323 patients in 2015-2020. The increase was particularly observed in patients aged 70 years or older. Changes in tumour subtypes were observed, notably with a rise in human epidermal growth factor receptor 2 (HER2)-positive cases but a steady distribution of estrogen receptor (ER) status. Diagnostic practices changed over the two decades, with 6% evaluated with PET/CT (positron emission tomography-computed tomography) or CT (computed tomography) with a bone evaluation in 2000-2004 and 65% in 2015-2020. Overall survival (OS) improved from 23 months in 2000-2004 to 33 months in 2015-2020. In patients with ER-positive and HER2-positive disease, the multivariable model showed improved survival by year of diagnosis, and further, patients with ER-negative/HER2-negative disease fared worse the first 2 years after diagnosis. Our study delineates changes in the treatment and survival of pMBC over two decades. Stage migration, screening introduction, and changes in registration practice, however, prevent a valid assessment of a possible causal relationship.

Statin use and risks of breast cancer recurrence and mortality.

Preclinical evidence suggests improved breast cancer survival associated with statin use, but findings from observational studies are conflicting and remain inconclusive. The objective of this study was to assess the association between statin use after cancer diagnosis and cancer outcomes among breast cancer patients. In this retrospective cohort study, 38,858 women aged ≥66 years who were diagnosed with localized and regional stage breast cancer from 2008 through 2017 were identified from the linked Surveillance, Epidemiology, and End Results Medicare database. Statin use was ascertained from Medicare Part D pharmacy claims data. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between post-diagnosis statin use and risks of breast cancer recurrence and breast cancer-specific mortality. Over a median follow-up of 2.9 years for recurrence and 3.7 years for mortality, 1446 women experienced a recurrence, and 2215 died from breast cancer. The mean duration of post-diagnosis statin use was 2.2 years. Statin use post-diagnosis was not associated with recurrence risk (HR, 1.05; 95% CI, 0.91-1.21), but was associated with a reduced risk of cancer-specific mortality (HR, 0.85; 95% CI, 0.75-0.96). The reduction was more pronounced in women with hormone receptor-positive/human epidermal growth factor receptor 2-negative breast cancer (HR, 0.71; 95% CI, 0.57-0.88). These findings suggest that post-diagnosis statin use is associated with improved cancer-specific survival in women with breast cancer and should be confirmed in randomized trials of statin therapy in breast cancer patients.

Triple-Negative Breast Cancer in a Young 23-Year-Old Woman with BRCA Mutation A about A Case and Literature Review

Triple-negative breast cancer (estrogen receptor negative, progesterone receptor negative and HER2 negative) is a particularly high-risk breast cancer which does not receive specific therapy targeting these proteins. We report the case of a 23-year-old patient diagnosed with triple-negative breast cancer of the left breast with a family history of breast cancer and carrying a BRCA1 mutation. The classification of breast cancer based on genomic data is required to allow us to optimize therapies and improve the management of breast cancer patients.

Abstract PO5-01-08: The impact of Human Epidermal growth factor Receptor 2 (HER2) expression by RT-PCR on tumor characteristics and outcome in estrogen receptor (ER) positive, HER2 negative early-stage breast cancer

Abstract Background: The role of HER2 expression in HER2 negative breast cancer is evolving. Whether HER2 expression has an impact on ER positive, HER2 negative early-stage breast cancer in unclear. Oncotype DX assay Recurrence Score comprises of standardized quantitative HER2 mRNA expression levels by RT-PCR. The objective of this study was to investigate the impact of Oncotype HER2 score on tumor characteristics and outcome. Methods: All women assigned to the Clalit Health Services registry between 2006 to 2011 with ER positive, HER2 negative early-stage breast cancer whose tumor were sent for oncotype were identified. Patients in which HER2 score was reported in the oncotype results were included. Differences in age, tumor characteristics and chemotherapy administration between lower HER2 score (H1), i.e. HER2 score ≤ 9.1, to higher HER2 score (H2), i.e. 9.2-10.7, were analyzed. 5-year Kaplan–Meier for distant recurrence free survival (DRFS) and overall survival (OS) were estimated and differences between H1 and H2 were evaluated. Analyses were repeated separately for node negative and for node positive (N mic and 1-3 lymph nodes) disease. Results: A total of 1535 patients were included, 948 patients with node negative disease and 587 with node positive disease. Of these, 814 and 721 patients were categorized to the H1 and H2 groups, respectively. Median follow-up was 5.4 years. The distribution of oncotype RS was different, with significantly lower proportion of patients with RS between 0-10 and higher proportion of RS above 25 in the H1 group compared to the H2 groups. This difference was identified both for patients with node negative and node positive disease (Table). The distributions of age, tumor size and histological subtype were comparable between the H1 and the H2 groups, both for node negative and node positive disease. Within each RS group, administration of chemotherapy was comparable between H1 and H2 groups, regardless of nodal involvement. DRFS and OS were not associated with HER2 score. For RS 0-25, node negative disease, 5-year DRFS was 96.2% in H1 and 96.4% in H2 groups (p=0.92) and 5-year OS was 97.2% in H1 and 98.1% in H2 groups (p=0.39). For RS &amp;gt;25, node negative disease, 5-years DRFS was 89% in H1 and 90.8% in H2 groups (p=0.33) and 5-year OS was 90.6% in H1 and 90.8% in H2 groups (p=0.7). Similarly, for node positive disease, DRFS and OS were comparable between H1 and H2 group in all subgroups. Conclusions: Low HER2 mRNA expression by Oncotype RT-PCR assay was associated with significantly high Oncotype RS. Patients' outcome was not directly affected by HER2 score and was determined by RS. Further study is desired to clarify the role of HER2 expression in early stage, luminal breast cancer. Table. Comparison of age and tumor characteristics between low (H1) and high (H2) HER2 score Citation Format: Hadar Goldvaser, Raz Mutai, Salomon Stemmer, Iryna Kuchuk, Margarita Tokar, Shani Paluch-Shimon, Rinat Yerushalmi, Karen Drumea, Ella Evron, Amir Sonnenblick, Einav Gal-Yam, Gil Bar Sela, Ayelet Shai, Rotem Merose, Avital Bareket-Samish, Lior Soussan-Gutman. The impact of Human Epidermal growth factor Receptor 2 (HER2) expression by RT-PCR on tumor characteristics and outcome in estrogen receptor (ER) positive, HER2 negative 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 PO5-01-08.

Abstract PO2-02-05: CDK4/6 inhibitor dalpiciclib combined with letrozole as neoadjuvant therapy in postmenopausal patients with hormone receptor-positive, HER2-negative stage II-III breast cancer: a single-arm exploratory trial

Abstract Background: Patients with HR-positive, HER2-negative breast cancer respond poorly to neoadjuvant chemotherapy. The phase 3 DAWNA-1 and DAWNA-2 studies have proved that adding dalpiciclib (a CDK4/6 inhibitor) to endocrine therapy can significantly improve progression-free survival in patients with hormone receptor (HR)-positive, HER2-negative advanced breast cancer. However, the evidence of dalpiciclib in the neoadjuvant setting is limited. This study aimed to explore the efficacy and safety of dalpiciclib plus letrozole as neoadjuvant therapy in in patients with HR-positive, HER2-negative stage II-III breast cancer. Methods: In this multicenter, single-arm exploratory trial (NCT05512780), adult postmenopausal women with HR-positive (estrogen receptor &amp;gt;10%), HER2-negative stage II-III invasive breast cancer were enrolled. Patients received oral dalpiciclib (150 mg on days 1-21 of each 28-day cycle) and oral letrozole (2.5 mg once daily) for 4 cycles, followed by surgery. The primary endpoint was objective response rate (ORR), assessed by investigator according to the Response Evaluation Criteria In Solid Tumors version 1.1. Secondary endpoints included complete cell cycle arrest (CCCA, defined as Ki-67 &amp;lt; 2.7% on day 15 of the first cycle) rate, total pathological complete response (tpCR; ypT0/is ypN0) rate, residual cancer burden (RCB) 0-I rate, and safety. Results: Between June 2022 and January 2023, 41 patients were screened at 9 sites, and 35 patients were enrolled and received at least one dose of study drug. The median age was 66 years (range, 52-83), and the median baseline Ki-67 level was 20% (range, 4%-40%). The majority of patients had T2 disease (65.7%), lymph node-positive disease (88.6%), and stage II disease (IIA: 45.7%; IIB: 40.0%). The ORR was 35.5% (11/31) at 8 weeks and 51.7% (15/29) at 16 weeks in patients with evaluable response. The CCCA rate was 70.0% (21/30) in patients with available data. Four patients refused surgery and chose to continue the drug therapy. Of 27 patients who had undergone surgery, one (3.7%) patient had tpCR and RCB 0. Of 35 patients, the most common adverse events were neutrophil count decreased (74.3%), white blood cell decreased (68.6%), anemia (34.3%), and fatigue (31.4%). The most common grade 3 or higher adverse event was neutrophil count decreased (45.7%). No febrile neutropenia or treatment-related deaths occurred. Conclusions: This is the first prospective study of neoadjuvant dalpiciclib in patients with HR-positive, HER2-negative breast cancer. The findings suggest the promising tumor response to neoadjuvant dalpiciclib plus letrozole in postmenopausal patients with HR-positive, HER2-negative breast cancer, with a manageable safety profile. This combination can effectively suppress the tumor cell proliferation, as reflected by change in Ki-67 level. Citation Format: Lina Zhang, Chao Yang, Jie Ma, Yuntao Li, Ruizhen Luo, Jianjun Han, Xiaochun Wang, Zhisheng Zhang, Li Ma, Haifeng Cai, Xiangshun Kong, Zunyi Wang, Xinping Zhou, Yueping Liu, JiaJie Shi, Yanshou Zhang, Meiqi Wang, Jiaxing Wang, Cuizhi Geng. CDK4/6 inhibitor dalpiciclib combined with letrozole as neoadjuvant therapy in postmenopausal patients with hormone receptor-positive, HER2-negative stage II-III breast cancer: a single-arm exploratory trial [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 PO2-02-05.

Abstract PO2-02-04: The Impact of Statins on Breast Cancer Specific Mortality in a Diverse Patient Population with Stage I-III Hormone Receptor Positive, HER2 Negative Breast Cancer

Abstract Hormone receptor-positive (HR+), HER2 negative (HER2−) breast cancer has a long-term risk of recurrence, compared with other breast cancer subtypes, which ultimately impacts mortality outcomes. Although adjuvant endocrine therapy plays an integral role in risk reduction, disparities persist—with Black women experiencing higher mortality rates compared to White women. Multiple studies have demonstrated that statin use can lead to a reduction in breast cancer mortality, but there is limited information in relation to the impact of statins among diverse patient populations in the United States. To assess whether statin use is associated with an improvement in breast cancer-specific mortality (BCSM), we conducted a large, observational study in women aged 66 and older diagnosed with Stage I–IIIC HR+, HER2- breast cancer between 2013 and 2017. We identified eligible women using the SEER-Medicare database and linked them to the BRIDGE (BReast cancer Investigation of Disparities in GEorgia) cohort, a survivorship cohort of the Georgia Cancer Registry. Patients needed to be continuously enrolled in Medicare Parts A, B, and D in the 12 months following a breast cancer diagnosis. We used Cox proportional hazards models to estimate the impact of statin use within 12 months of diagnosis on BCSM with adjustment for age, stage, and race using multivariable-adjusted hazard ratios (HRs). A total of 2483 participants were identified, and of those, 303 (12.2%) were statin users, 383 (15.4%) were non-Hispanic Black women, and 1564 (63%) resided in census tract with greater than or equal to 10% poverty levels at the time of diagnosis. Distribution of age, stage, and race were similar between statin and non-statin users. Of the statin users, 41/303 (13.5%) were non-Hispanic Black women. The majority of statin users were prescribed lipophilic statins alone (169; 55.8%), and atorvastatin was the most commonly prescribed statin. There was no association between statin use and BCSM (HR 1.09; 95% CI 0.62-1.90) in the multivariable-adjusted model. Although preliminary results suggest that there is no association between statin use and BCSM among women with Stage I–IIIC HR+, HER2− breast cancer, further analyses are planned to explore statin use as a time-varying exposure, which may provide additional insights into the potential relationship between statin use and BCSM. In addition, analyses examining potential heterogeneity by race, tumor and treatment characteristics, and comorbidities are forthcoming. Given the low cost and relative accessibility of statins, we anticipate these findings will inform the clinical management of women with operable breast cancer, increasing parity in outcomes and potentially narrowing race disparities. Citation Format: Ruth Sacks, Maya Bliss, Micah Streiff, Leah Moubadder, Maret Maliniak, Tsion Armidie, Lindsay Collin, Kevin Kalinsky, Lauren McCullough. The Impact of Statins on Breast Cancer Specific Mortality in a Diverse Patient Population with Stage I-III Hormone Receptor Positive, HER2 Negative 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 PO2-02-04.

Abstract GS02-01: Randomized phase 3 study of datopotamab deruxtecan vs chemotherapy for patients with previously-treated inoperable or metastatic hormone receptor-positive, HER2-negative breast cancer: Results from TROPION-Breast01

Abstract Background: The global, phase 3 TROPION-Breast01 trial (NCT05104866) assessed the TROP2-directed antibody-drug conjugate (ADC) datopotamab deruxtecan (Dato-DXd) compared with investigator’s choice of chemotherapy (ICC) in patients (pts) with inoperable or metastatic hormone receptor-positive, HER2-negative (HR+/HER2‒) breast cancer (BC). Primary results were presented at ESMO 2023 (Bardia A, et al. Abstract LBA11). Here we report expanded data from TROPION-Breast01. Methods: Pts aged ≥18 years who had inoperable or metastatic HR+/HER2‒ BC, had disease progression on endocrine therapy (ET) and for whom ET was unsuitable, and had received 1‒2 prior lines of systemic chemotherapy (CT), were eligible. Pts were randomized 1:1 to Dato-DXd (6 mg/kg Q3W) or ICC (eribulin, vinorelbine, capecitabine, or gemcitabine) until progression or unacceptable toxicity. The dual primary endpoints were progression-free survival (PFS) by blinded independent central review (BICR) per RECIST 1.1, and overall survival (OS). Results: In total, 732 pts were randomized: 365 to the Dato-DXd arm and 367 to ICC. At data cut-off (Jul 17, 2023), 93/39 pts in the Dato-DXd/ICC groups were ongoing treatment. Pts receiving Dato-DXd had significantly improved PFS vs ICC (HR 0.63 [95% CI 0.52‒0.76]; p&amp;lt;0.0001). Hazard ratios for PFS favored Dato-DXd over ICC across prespecified pt subgroups, including prior lines of CT in the metastatic setting (1 vs 2), prior use of CDK4/6 inhibitor (≤12 months vs &amp;gt;12 months), prior use of endocrine therapy in the metastatic setting ( &amp;lt;6 months vs ≥6 months) and brain metastases (yes vs no). OS data were not mature at this data cut-off. In the Dato-DXd vs ICC arms, 192 (53%) vs 247 (67%) pts had received a subsequent therapy after study treatment discontinuation, including 15 (4%) vs 52 (14%) who received subsequent ADC therapy, and 165 (45%) vs 186 (51%) who received subsequent CT. Median time to first subsequent therapy was 8.2 months in the Dato-DXd arm vs 5.0 months in the ICC arm (HR 0.53 [95% CI 0.45–0.64). Overall, rate of grade ≥3 treatment-related adverse events (TRAEs) with Dato-DXd was less than half that with ICC. The secondary patient-reported outcome endpoints showed that time to deterioration in physical functioning, pain, and global health status/quality of life were delayed in the Dato-DXd arm compared with ICC. Conclusions: TROPION-Breast01 met its dual primary endpoint of PFS, demonstrating statistically significant and clinically meaningful improvement in PFS with Dato-DXd compared with ICC across all subgroups. Overall, the safety profile and QoL with Dato-DXd was favorable compared with ICC. These data support Dato-DXd as a potential new therapeutic option for pts with inoperable or metastatic HR+/HER2‒ BC who have received 1‒2 prior lines of CT. Citation Format: Aditya Bardia, Komal Jhaveri, Seock-Ah Im, Michelino De Laurentiis, Binghe Xu, Sonia Pernas, Giuliano Borges, David Cescon, Masaya Hattori, Yen-Shen Lu, Noelia Martínez-Jáñez, Erika Hamilton, Shusen Wang, Junji Tsurutani, Kevin Kalinsky, Lu Xu, Sabrina Khan, Neelima Denduluri, Hope Rugo, Barbara Pistilli. Randomized phase 3 study of datopotamab deruxtecan vs chemotherapy for patients with previously-treated inoperable or metastatic hormone receptor-positive, HER2-negative breast cancer: Results from TROPION-Breast01 [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 GS02-01.

Abstract PO3-01-12: Clinicopathologic Factors affecting response in patients with Estrogen receptor-positive and Human Epidermal Growth Factor Receptor-negative breast cancer receiving neoadjuvant chemotherapy

Abstract Background: The evolution of Neoadjuvant chemotherapy(NAC) regimen has enabled the down-staging of locally advanced breast cancer, allowing patients to undergo breast conserving surgery. NAC is known to be effective in triple-negative breast cancer (TNBC) and HER2-positive breast cancer. However, the role of NAC in hormone receptor-positive and HER2-negative (HR+HER2-) breast cancer patients remains unclear. In this study, we aimed to explore the utility of NAC for estrogen receptor-positive and HER2-negative (ER+HER2-) breast cancer patients. Methods: Clinical data were collected from 120 patients who were diagnosed with estrogen receptor (ER)-positive and HER2-negative breast cancer and received neoadjuvant chemotherapy between July, 2017 and April, 2023 at Seoul St Mary’s Hospital (Seoul, Korea). We analyzed the factors that affect clinical response subgroups, including pathologic complete response (pCR), partial response (PR), stable disease(SD), and progressive disease (PD), following neoadjuvant chemotherapy. The median follow-up period was 17 months. &amp;lt; Results: Among 120 patients after NAC, 5.8% achieved pCR, while 67.5% had a partial response. The median age at the time of surgery was 55 years at pCR group, 49 years at PR group, 47 years at SD group, and 49 years at PD group. Although the age of patients achieving pathological complete response was higher, this differences was not statistically significant. Patients achieving pCR had a higher incidence of progesterone receptor (PR) negativity (pCR 71.4% vs PR 30.9%, p=0.011) and higher levels of Ki-67 expression than those who did not achieve pCR (71.7% vs 35.6%, p=0.003). Also, there was no significant difference in Androgen receptor (AR) and HER-2 expression between the groups. Tumor size was also significantly associated with clinical response (p=0.003). However, no differences in clinical response was observed between patients with lymph node metastasis (p=0.221). Our analysis of 107 patients who were clinically N positive before NAC showed that the Ki-67 index level was the only factor found to affect nodal pCR. In addition, in the non-pCR group, patients with a Ki-67 index of less than 20% after neoadjuvant had a significantly better disease-free survival (5yr DFS, 79.8% vs 65.9%, p=0.039) Conclusion: Our analysis revealed that patients with higher levels of Ki-67 and lower level of PR expression were more likely to achieve pCR or PR. Also, decrease in Ki-67 index was confirmed to be an important prognostic factor of ER+ HER2- breast cancer. A combination of clinical and molecular factors, such as tumor size, progesterone receptor expression, and Ki-67 expression, can be used to optimize treatment plans and improve outcomes for the patient population. Citation Format: Jin Ah Lee, Young Joo Lee, Dooreh Kim, Chang Ik Yoon, Woo-Chan Park, Soo Youn Bae. Clinicopathologic Factors affecting response in patients with Estrogen receptor-positive and Human Epidermal Growth Factor Receptor-negative breast cancer receiving neoadjuvant chemotherapy [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 PO3-01-12.

Abstract PO5-04-14: Quality of Life (QoL) among metastatic hormone receptor positive, HER2 negative breast cancer patients during first line systemic treatment

Abstract Background Current international guidelines recommend endocrine therapy combined with a CDK4/6 inhibitor as the preferred first line systemic treatment in patients diagnosed with metastatic hormone receptor positive (HR), HER2 negative breast cancer (BC). Randomized controlled trials that led to the approval of these agents in the first line disease setting are derived from controlled environments and selected patients. We aimed to assess real-world patients’ characteristics, safety and health related quality of life in a non-select cohort of patients being managed in a Brazilian private Cancer Center. Methods: We performed a cross sectional study at Beneficencia Portuguesa de Sao Paulo evaluating quality of life among patients with metastatic HR+/HER2 negative treated in the first line disease setting. Inclusion criteria included patients that received the combination of a CDK4/6i with any endocrine therapy (ET) between January 2018 and April 2023. Primary endpoint was quality of life assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and EORTC QLQ-BR23, it is baseline, there is only one measurement for each patient. Results: We analyzed 72 patients who meet the inclusion criteria. Median age at diagnosis was 49 years old (ranging from 31 to 91). Approximately half of the population was premenopausal (51%). Palbociclib and abemaciclib were the most commonly used CDK4/6i, with 42 and 35% of patients, respectively. ECOG performance status was zero or one in almost the entire patient population analyzed (97%). 53% of the patients were diagnosed as de novo metastatic BC. Table 1 and 2 summarize the patients characteristics. Mean global health status was 75.4, with social and cognitive functioning scoring the highest (Mean 78.6 and 79.1, respectively). The most distressing symptom among the symptom scale was fatigue (Mean 27.2). Most symptoms and functioning scales did not meet the threshold for clinically meaningful differences between the different CDK4/6 inhibitors. Conclusion: Real-world data from our study is consistent with the historical expected health related quality of life among patients diagnosed with HR+/HER2 negative metastatic BC in the first line disease setting. Table. Citation Format: Débora Gagliato, Julio Antonio Araujo, Bianca Milena Verboski, Guilherme William Marcelino, Fabiana Nogueira Momberg, Gilmara Silveira da Silva, Rozana Mesquita Ciconelli, Antônio Buzaid. Quality of Life (QoL) among metastatic hormone receptor positive, HER2 negative breast cancer patients during first line systemic 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 PO5-04-14.

Abstract PO4-16-11: De-escalation of anthracyclines during adjuvant therapy based on Oncotype RS: A single institution experience in Mexico City

Abstract Introduction: In Mexico, hormone positive HER2 negative breast cancer is the most frequent subtype, accounting for 76.6% of cases. For patients undergoing local control management through surgery; adjuvant chemotherapy is usually followed depending on different risk factors. In order to avoid overtreatment, different genomic firms have been approved aiding in a more objective decision. One of these genomic firms is the Oncotype Recurrence score. The TAILORx and RxPONDER trials have provided guidance in determining which patients are candidates for chemotherapy depending on their menopausal status. However, it has not yet been determined whether patients requiring chemotherapy can receive an anthracycline-free regimen. In the Plan B clinical trial, a non-inferiority analysis was conducted on early-stage breast cancer patients who received anthracycline-based or non-anthracycline-based chemotherapy, with the non-anthracycline regimen being non-inferior, including patients with a RS &amp;gt; 25. We intend to reevaluate these findings in our Mexican population. Methods: We evaluated 217 patients with early stage hormone sensitive HER2 negative breast cancer who had an Oncotype Recurrence score (RS) result. This retrospective cohort study took place by analyzing electronic records from January 2011 to December 2017 with patients treated at the National Cancer Institute in Mexico City. We included patients 18 years of age or older, any sex with an Oncotype RS ≥ 16 in premenopausal patients or ≥ 26 in postmenopausal patients who received adjuvant chemotherapy with or without anthracyclines. Our primary endpoint was iDFS comparing TC vs AC-T. Overall survival was set as a secondary endpoint. Results: Of the 217 patients with an Oncotype recurrence score, only 46 patients received adjuvant chemotherapy of which 71.7% were premenopausal with a median age of 45 years. Stage II was the most common stage with 91.3% of the population, as well as ductal carcinoma with 82.6%. All patients had positive lymph nodes, 54.3% at least 1 lymph node. Most patients received AC-T adjuvant chemotherapy (60.9%), and only 39.1% received TC. Of the 46 patients analyzed, only 19.6% (9) had a recurrence upon follow-up (Table 1). Median time of follow up was 87.5 months. Difference in Disease free survival could not be established between patients receiving AC-T with 105 months (CI 95% 94.36-117.43 months) vs TC with 94.09 months (CI 95% 83.85-104.34 months, &amp;lt; p.918) (Figure 1). Overall survival did not have a statistical difference between both chemotherapy regimens, p&amp;lt; 0.649 (Figure 2A), when comparing Oncotype RS, overall survival was better in those with Oncotype OS &amp;lt; 26, p&amp;lt; 0.023 (Figure 2B). Discusion As described previously in the Plan B trial, TC was non inferior to the conventional adjuvant regimen of AC-T in Hormone positive HER2 negative early-stage breast cancer. Our results tend to show similar results when compared to the Plan B. An important aspect to our study was that 71.7% of our patients were premenopausal, where in the Plan B trial only 35% were premenopausal, considered a higher risk group of patients. Although a statical difference couldn´t be established due to our small sample size, in DFS or OS when comparing the chemotherapy regimen. Premenopausal patients with an Oncotype RS &amp;lt; 26 could receive an anthracycline free regimen, without impact in their overall survival. Larger prospective studies are necessary to assure this conclusion. Figure 1 DFS (TC vs AC-T) Figure 2 A and B Overall Survival Table 1 (Baseline characteristics) Citation Format: Carlos Arturo González Núñez, Paula Cabrera-Galeana, Juan Enrique Bargalló Rocha, Rafael Vazquez-Romo, Sergio Aguilar-Villanueva, Alexandra Garcilazo, Areli Velazquez-Martinez, Andrea Maliachi, Ruben Rodriguez, Esmeralda Romero-Bañuelos. De-escalation of anthracyclines during adjuvant therapy based on Oncotype RS: A single institution experience in Mexico City [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 PO4-16-11.