Estrogen Receptor Status Research Articles

Abstract PO4-26-04: Immunolocalization of cytoplasmic ER in ER-negative breast carcinoma as a potent favorable prognostic predictor

Abstract Background: It is known that estrogen receptor (ER) has extranuclear signaling functions in addition to classical genomic pathway, and estrogenic actions have been reported in ER-negative breast carcinoma cells. However, significance of cytoplasmic-ER immunoreactivity has not been reported in ER-negative breast carcinoma tissues. Methods: We immunolocalized cytoplasmic ER in 155 ER-negative breast carcinoma tissues and evaluated its clinicopathological significance including the prognosis. As a comparative cohort set, we also used 142 ER-positive breast carcinomas. Results: Cytoplasmic-ER immunoreactivity was detected in the carcinoma cells, but not in the non-neoplastic mammary epithelium. Cytoplasmic-ER immunoreactivity was positive in the 35 out of 155 (23%) ER-negative breast carcinoma cases, whereas it was detected only in 2 out of 142 (1.4%) ER-positive cases. Cytoplasmic ER status was positively associated with cytoplasmic-PR status, but inversely associated with Ki67 labeling index or distant free-relapse survival rate. Moreover, cytoplasmic-ER status turned out to be an independent good prognostic factor for both distant relapse-free survival and breast cancer specific survival. Conclusion: These findings suggested that cytoplasmic ER plays important roles in the ER-negative breast carcinoma, and cytoplasmic ER is a potent good prognostic factor. (accepted in Acta Histochemica et Cytochemica, 2023/Jun/27) Citation Format: Akiko Ebata, Takashi Suzuki, Narumi Harada-Shoji, Yohei Hamanaka, Minoru Miyashita, Erina Iwabuchi, Kiyoshi Takagi, Yasuhiro Miki, Hiroshi Tada, Takanori Ishida. Immunolocalization of cytoplasmic ER in ER-negative breast carcinoma as a potent favorable prognostic predictor [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 PO4-26-04.

Abstract PO2-07-07: The role of PET imaging with [18F]16α-fluoro-17β-fluoroestradiol in predicting response to endocrine therapies in patients with breast cancer

Abstract Background Fluoroestradiol F18 is a radioactive diagnostic agent (18F-FES) used with positron emission tomography (PET) imaging to detect estrogen-receptor (ER)-positive lesions in patients with breast cancer. Convened by the Society of Nuclear Medicine and Molecular Imaging (SNMMI), an expert working group published appropriate use criteria (AUC) for 18F-FES PET including, but not limited to, use of 18F-FES for selection of endocrine therapies. Quantitative determination of ER status, and thus treatment response, has the potential to prevent ineffective courses of endocrine therapies and associated therapeutic/financial burden. This meta-analysis reviewed the AUC-cited studies to assess the utility of 18F-FES in predicting treatment response to endocrine therapies. Methods Eight studies cited in the AUC were selected based on having comparable 18F-FES PET standardized uptake values (SUV) and progression-free survival (PFS) measures, and one additional study was included upon further systematic search of the same selected parameters defined in the AUC. With the nine studies (n = 327), we conducted three investigations to explore the association between: (1) the patient baseline 18F-FES PET SUVmean, across all lesions or across up to seven of the most intense lesions, and patient response to endocrine therapy (response/no response); (2) in the same population as investigation 1, the change (%) in 18F-FES PET SUV from baseline to at 7 to 10 days post-treatment; (3) the 18F-FES interlesional heterogeneity and PFS (months). Interlesional heterogeneity was qualitatively defined as patients displaying both 18F-FES positive and negative lesions versus those with all FES-positive lesions. Results A fixed effects model was used to analyze three studies (n = 102). Findings reveal that patients who responded to endocrine therapy had a significantly higher baseline SUVmean versus non-responders (mean difference 0.91; CI 95% 0.49 to 1.34; P < 0.001); a sensitivity analysis was conducted via random effects modelling and revealed similar results (mean difference 0.92; CI 95% 0.48 to 1.36; P < 0.001). This was consistent with findings from an additional analysis performed on two papers (n = 62), whereby odds ratio estimates indicated that a response to therapy is 89% less likely to occur when baseline 18F-FES SUVmax is < 1.5 (OR 0.11; CI 95% 0.02 to 0.72 P = 0.02). Findings from the analysis of mean percentage change in 18F-FES SUV from baseline to 7-10 days post-treatment initiation showed no significant difference in the percentage change of SUV observed between responders and non-responders (mean difference -0.22; 95% CI -0.69 to 0.26; P = 0.37). The final heterogeneity analysis revealed higher median PFS in all FES-positive cohort, suggesting that this group may respond better to endocrine therapy (Table 1). Conclusion The AUC states that the presence of ER by immunohistochemistry may not be the optimal predictive biomarker for the success of endocrine therapies. Our findings support this statement, as a significantly higher baseline SUVmean of 18F-FES may serve as a predictive biomarker for endocrine therapy response. Patients with a 18F-FES lesion SUVmax < 1.5 are 89% less likely to respond to endocrine therapies; patients demonstrating heterogeneity (FES+/FES- lesions) have a lower median PFS, reinforcing the predictive value of 18F-FES. Table 1. Median PFS scores from FES heterogeneity analysis *Patients with all FES positive lesions were categorised by the median ratio of FES/FDG SUVmax into low FES/FDG ( <0.96), and high FES/FDG (>0.96); only patients with FES/FDG of >0.96 were included in the positive lesions arm. Citation Format: Nicholas DiGregorio, Christine Brand, Dustin Dunham, Eleanor McManus. The role of PET imaging with [18F]16α-fluoro-17β-fluoroestradiol in predicting response to endocrine therapies in patients with 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 PO2-07-07.

The Utility of the Cachexia Index and the Modified Glasgow Score in Young Patients With Breast Cancer.

Background Breast cancer is the most common cancer in women. Body composition and inflammatory markers are increasingly important for predicting cancer prognosis. The Cancer Cachexia Index (CXI) and the modified Glasgow Prognostic Score (GPS) are two new markers evaluating prognosis in cancer. In this study, we evaluated the utility of the CXI and the modified GPS in young patients with breast cancer. Methods Eighty patients diagnosed between 2012 and 2023 were included in the study. The following information was recorded: patient features, pathological subtype, estrogen receptor and human epidermal growth factor receptor-2 (HER-2) status, disease stage, therapies, disease recurrence, and last control or death date. The CXI and the modified GPS were calculated using clinical data, includingskeletal muscle index, albumin, C-reactive protein, andneutrophil-to-lymphocyte ratio. Results There were no differences in overall survival with respect to the CXI in the study population (p=0.96). Only stage 4 patients showed statistically significant survival differences according to the CXI (p=0.046). Although the median survival time was not reached for the modified GPS groups, there was a statistical overall survival difference favoring the negative group (p=0.017). No significant differences were observed in disease-free survival due to the CXI (p=0.128). In multivariate analysis, no factors, including the modified GPS and the CXI, influenced overall survival. There was a significant effect of the modified GPS and body mass index on recurrence (p=0.037; p=0.034). The CXI had a non-significant marginal p-value (p=0.074). Conclusion Our study showed that the modified GPS may be related to disease-free survival and overall survival, whereas the CXI has a more prominent prognostic effect on overall survival in advanced-stage breast cancers. In early-stage and young patients, optimization of risk scores is lacking.

A new prediction nomogram of non-sentinel lymph node metastasis in cT1-2 breast cancer patients with positive sentinel lymph nodes

We aimed to analyze the risk factors and construct a new nomogram to predict non-sentinel lymph node (NSLN) metastasis for cT1-2 breast cancer patients with positivity after sentinel lymph node biopsy (SLNB). A total of 830 breast cancer patients who underwent surgery between 2016 and 2021 at multi-center were included in the retrospective analysis. Patients were divided into training (n = 410), internal validation (n = 298), and external validation cohorts (n = 122) based on periods and centers. A nomogram-based prediction model for the risk of NSLN metastasis was constructed by incorporating independent predictors of NSLN metastasis identified through univariate and multivariate logistic regression analyses in the training cohort and then validated by validation cohorts. The multivariate logistic regression analysis revealed that the number of positive sentinel lymph nodes (SLNs) (P < 0.001), the proportion of positive SLNs (P = 0.029), lymph-vascular invasion (P = 0.029), perineural invasion (P = 0.023), and estrogen receptor (ER) status (P = 0.034) were independent risk factors for NSLN metastasis. The area under the receiver operating characteristics curve (AUC) value of this model was 0.730 (95% CI 0.676–0.785) for the training, 0.701 (95% CI 0.630–0.773) for internal validation, and 0.813 (95% CI 0.734–0.891) for external validation cohorts. Decision curve analysis also showed that the model could be effectively applied in clinical practice. The proposed nomogram estimated the likelihood of positive NSLNs and assisted the surgeon in deciding whether to perform further axillary lymph node dissection (ALND) and avoid non-essential ALND as well as postoperative complications.

Prognostic value of molecular classification in stage IV endometrial cancer

ObjectivesMultiple studies have proven the prognostic value of molecular classification for stage I–III endometrial cancer patients. However, studies on the relevance of molecular classification for stage IV endometrial cancer patients...

Texture analysis using non-contrast MRI to predict estrogen receptor status in breast cancer lesions: Is it feasible?

We aimed to evaluate the feasibility of non-contrast-enhanced T1 sequence in texture analysis of breast cancer lesions to predict their estrogen receptor status. The study included 85 pathologically proven breast cancer lesions in 53 patients. Immunohistochemical studies were performed to determine the estrogen receptor status (ER). Lesions were divided into two groups: ER+ve status and ER-ve status. Texture analysis using the second-order analysis features [The Co-occurrence matrix (11 features)] was applied on both T1 and dynamic contrast-enhanced (DCE) MRI images for each lesion. Texture features gained from both T1 and DCE images were analyzed to obtain cut-off values using ROC curves to sort lesions according to their estrogen receptor status. Angular second momentum and some of the entropy-based features showed statistically significant cut-off values in differentiation between the two groups [P-values for pre- and post-contrast images for AngSecMom (0.001, 0.008), sum entropy (0.003,0.005), and entropy (0.033,0.019), respectively]. On comparing the AUCs between pre- and post-contrast images, we found that differences were statistically insignificant. Sum of squares, sum variance, and sum average showed statistically significant cut-off points only on pre-contrast images [P-values for sum of squares (0.018), sum variance (0.024), and sum average (0.039)]. Texture analysis features showed promising results in predicting estrogen receptor status of breast cancer lesions on non-contrast T1 images.

Significance of Estrogen/Progesterone Receptor Expression in Metaplastic Breast Carcinoma.

Metaplastic breast carcinoma (MBC) is a rare subgroup of breast neoplasms associated with adverse outcomes because of its aggressive nature. Typically, MBCs show triple-negative hormone receptor (HR) status. Determining the HR status of breast cancer is an integral part because it is an important prognostic factor and helps in the treatment course of the disease. This study aimed to determine the HR status of MBC, its significance, and its association with various clinicopathological parameters. This was a retrospective study conducted at the Department of Histopathology, Liaquat National Hospital. A total of 140 biopsy-proven cases of MBC were enrolled in the study. Clinical and pathological data were retrieved from the institutes' archives. Immunohistochemical studies were conducted to determine the estrogen receptor (ER) and progesterone receptor (PR) status. The mean age of MBC in our population was found to be 52.18 ± 12.19 years. The HR positivity rate in our population was found to be 32.9%. A significant association was found between HR status and tumor laterality, tumor size, tumor grade, tumor stage, and recurrence. ER/PR-negative MBCs were most probably associated with higher grade and higher tumor stage and were larger in size (6.62 ± 3.43 cm) than ER/PR-positive MBCs (4.20 ± 1.88 cm). Moreover, ER/PR-positive MBCs showed a higher recurrence rate than ER/PR-negative MBCs (43.5% vs. 25.5%, respectively). No statistically significant relationship was found between HR status and patient age, histological subtype, or survival rate. MBC is a rare breast neoplasm. MBC was found to be triple negative in most cases, but a significant percentage were HR (ER/PR) positive. Moreover, we found an association between HR status and various clinicopathological features, indicating that HR status is a significant predictor of MBC prognosis.

Metastatic patterns and hormone receptor status among breast cancer patients in Tanzania

Introduction: Metastatic breast cancer is a common presentation in Tanzania. Estrogen-receptor (ER)-positive tumors are known to metastasize to the bones and require hormonal treatment as first-line therapy. Challenges with accessing immunohistochemistry services can delay information on breast cancer subtypes, further delaying treatment with effective hormonal therapy. Objectives: This study aimed to assess the pattern of distribution of metastatic lesions in patients with metastatic breast cancer and evaluate its association with their hormone and HER-2 status, which could help provide recommendations on the use of front-line hormone therapy in areas where access to immunohistochemistry is a challenge. Methods: A retrospective study covering histologically confirmed breast cancer patients in 2020 with metastatic lesions and complete medical records at Ocean Road Cancer Institute. Clinical information on the number, state and sites of metastasis, presence of symptoms and treatment received, and pathological variables, including histology, ER, PR and HER-2 status, were documented. Results: Forty-nine (96.1%) of 51 patients analysed were female, with a mean age of 49.5 years. 47% presented with up-front metastatic disease. Lung was the most common metastatic site (76.5%) followed by bone/spine (53%). About half the patients had multiple sites involved. ER-positive tumors accounted for 47%, PR positive for 31% and HER-2 positive 39.2%. ER-positive tumors were more likely to present as a recurrence than up-front metastasis. ER-positive tumors were significantly more likely to be associated with bone and spine metastasis (59%) compared to ER-negative tumors (29%) Conclusion: The clinical and pathological features of MBC in Tanzanian women are similar in many ways to those in other African regions. However, the ER positivity rate is lower. This study found a significant association between ER-positive tumours and skeletal metastasis, which has implications for the up-front treatment of these patients, especially where access to immunohistochemistry can be a challenge.

E-cadherin Expression in Invasive Mammary Carcinoma

Abstract Background: E-cadherin is an adhesion molecule that is frequently expressed in normal epithelial tissues. It is essential for many cellular processes, including organ formation, stratification, and epithelial polarization. Objective: This study examines E-cadherin expression for subclassifying invasive breast cancer. E-cadherin expression also decreased with age, histopathological type, grade, and stage. Materials and Methods: This prospective study included 249 breast cancer patients who underwent surgery at a private facility in Baghdad, Iraq. The patients’ clinical data were analyzed, focusing on age, histopathological type, tumor grade, and tumor stage. Immunohistochemical and histopathological processing and staining were performed to evaluate E-cadherin status in the tumor cells. Results: Mean age of patients 47.92 ± 10.79 years, most age group 40–49 (35.7%), most histopathological type of breast cancer invasive ductal carcinoma (IDC; 81.1%), grade II (67.9%), and stage II (78.3%). Patients have +3 E-cadherin (79.5%). Grade III breast cancer patients have 98% +3 E-cadherin. E-cadherin is unrelated to age, histopathological type, or stage. Conclusion: Decreased E-cadherin expression in breast cancer is associated with higher tumor grade and estrogen receptor status. However, its significance as a prognostic or predictive marker is limited in IDC and special varieties. The study found no significant correlation between E-cadherin expression and age group, histopathological type, or breast cancer stage.

Postpartum Breast Cancer and Survival in Women With Germline BRCA Pathogenic Variants

In young-onset breast cancer (YOBC), a diagnosis within 5 to 10 years of childbirth is associated with increased mortality. Women with germline BRCA1/2 pathogenic variants (PVs) are more likely to be diagnosed with BC at younger ages, but the impact of childbirth on mortality is unknown. To determine whether time between most recent childbirth and BC diagnosis is associated with mortality among patients with YOBC and germline BRCA1/2 PVs. This prospective cohort study included women with germline BRCA1/2 PVs diagnosed with stage I to III BC at age 45 years or younger between 1950 and 2021 in the United Kingdom, who were followed up until November 2021. Data were analyzed from December 3, 2021, to November 29, 2023. Time between most recent childbirth and subsequent BC diagnosis, with recent childbirth defined as 0 to less than 10 years, further delineated to 0 to less than 5 years and 5 to less than 10 years. The primary outcome was all-cause mortality, censored at 20 years after YOBC diagnosis. Mortality of nulliparous women was compared with the recent post partum groups and the 10 or more years post partum group. Cox proportional hazards regression analyses were adjusted for age, tumor stage, and further stratified by tumor estrogen receptor (ER) and BRCA gene status. Among 903 women with BRCA PVs (mean [SD] age at diagnosis, 34.7 [6.1] years; mean [SD] follow-up, 10.8 [9.8] years), 419 received a BC diagnosis 0 to less than 10 years after childbirth, including 228 women diagnosed less than 5 years after childbirth and 191 women diagnosed 5 to less than 10 years after childbirth. Increased all-cause mortality was observed in women diagnosed within 5 to less than 10 years post partum (hazard ratio [HR], 1.56 [95% CI, 1.05-2.30]) compared with nulliparous women and women diagnosed 10 or more years after childbirth, suggesting a transient duration of postpartum risk. Risk of mortality was greater for women with ER-positive BC in the less than 5 years post partum group (HR, 2.35 [95% CI, 1.02-5.42]) and ER-negative BC in the 5 to less than 10 years post partum group (HR, 3.12 [95% CI, 1.22-7.97]) compared with the nulliparous group. Delineated by BRCA1 or BRCA2, mortality in the 5 to less than 10 years post partum group was significantly increased, but only for BRCA1 carriers (HR, 2.03 [95% CI, 1.15-3.58]). These findings suggest that YOBC with germline BRCA PVs was associated with increased risk for all-cause mortality if diagnosed within 10 years after last childbirth, with risk highest for ER-positive BC diagnosed less than 5 years post partum, and for ER-negative BC diagnosed 5 to less than 10 years post partum. BRCA1 carriers were at highest risk for poor prognosis when diagnosed at 5 to less than 10 years post partum. No such associations were observed for BRCA2 carriers. These results should inform genetic counseling, prevention, and treatment strategies for BRCA PV carriers.

Radiomics Analysis of Contrast-Enhanced Breast MRI for Optimized Modelling of Virtual Prognostic Biomarkers in Breast Cancer.

Breast cancer clinical stage and nodal status are the most clinically significant drivers of patient management, in combination with other pathological biomarkers, such as estrogen receptor (ER), progesterone receptor or human epidermal growth factor receptor 2 (HER2) receptor status and tumor grade. Accurate prediction of such parameters can help avoid unnecessary intervention, including unnecessary surgery. The objective was to investigate the role of magnetic resonance imaging (MRI) radiomics for yielding virtual prognostic biomarkers (ER, HER2 expression, tumor grade, molecular subtype, and T-stage). Patients with primary invasive breast cancer who underwent dynamic contrast-enhanced (DCE) breast MRI between July 2013 and July 2016 in a single center were retrospectively reviewed. Age, N-stage, grade, ER and HER2 status, and Ki-67 (%) were recorded. DCE images were segmented and Haralick texture features were extracted. The Bootstrap Lasso feature selection method was used to select a small subset of optimal texture features. Classification of the performance of the final model was assessed with the area under the receiver operating characteristic curve (AUC). Median age of patients (n = 209) was 49 (21-79) years. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the model for differentiating N0 vs N1-N3 was: 71%, 79%, 76%, 74%, 75% [AUC = 0.78 (95% confidence interval (CI) 0.72-0.85)], N0-N1 vs N2-N3 was 81%, 59%, 24%, 95%, 62% [AUC = 0.74 (95% CI 0.63-0.85)], distinguishing HER2(+) from HER2(-) was 79%, 48%, 34%, 87%, 56% [AUC = 0.64 (95% CI 0.54-0.73)], high nuclear grade (grade 2-3) vs low grade (grades 1) was 56%, 88%, 96%, 29%, 61% [AUC = 0.71 (95% CI 0.63-0.80)]; and for ER (+) vs ER(-) status the [AUC=0.67 (95% CI 0.59-0.76)]. Radiomics performance in distinguishing triple-negative vs other molecular subtypes was [0.60 (95% CI 0.49-0.71)], and Luminal A [0.66 (95% CI 0.56-0.76)]. Quantitative radiomics using MRI contrast texture shows promise in identifying aggressive high grade, node positive triple negative breast cancer, and correlated well with higher nuclear grades, higher T-stages, and N-positive stages.

Meningioma Prognostic Tool Based on Correlation of Histopathological Grading and Immunohistochemistry.

Meningiomas are slow-growing brain neoplasms classified into three grades based on morphological criteria. While these grades are simple, they do not always correlate with patient outcomes. This study aimed to evaluate the status of estrogen receptor (ER), progesterone receptor (PR), and proliferation marker Ki-67/molecular immunology borstel-1 (MIB-1) in the three grades of meningioma. We evaluated the data of meningioma patients who were seen in our tertiary center over 10 years-8.5 years retrospectively and 1.5 years prospectively. Their archival hematoxylin and eosin stained slides were reviewed and re-graded according to the World Health Organization 2021 criteria. Immunohistochemical analysis for ER, PR, and Ki-67 was performed on all grade 2 and grade 3 meningiomas and 30 cases of grade 1 formalin-fixed, paraffin-embedded samples. Of the 276 cases included in the study, there were 231 (83.7%) cases of grade 1 meningioma, 34 (12.3%) cases of grade 2, and 11 (4.0%) cases of grade 3. ER was positive in 26.0% of grade 1 tumors, 5.8% of grade 2, and 0.0% of grade 3. PR was positive in 70.0% of grade 1 tumors, 20.0% of grade 2, and 18.0% of grade 3. The Ki-67/MIB-1 labeling index (LI) was 2.1 in grade 1, 6.3 in grade 2, and 13.4 in grade 3 tumors. For both PR and Ki-67, the differences between grades 1, 2, and 3 tumors were significant (p < 0.001). There was a significant inverse relationship between mean Ki-67 LI and PR status, with increasing grade of tumor. Ki-67/MIB-1 LI has significant positive correlations with meningioma grade and its recurrence, which makes it a useful auxiliary method for the routine assessment of meningiomas, especially in patients with borderline atypia. The expression of PR, on the other hand, is a positive prognostic indicator and has a substantial correlation with histological grade. In cases of subtotal resection, high proliferative/recurrence rates, and borderline histopathology, the PR status in combination with the MIB-1 LI can offer insights into the behavior and the recurrence probability of a meningioma.

Effect of capecitabine as monotherapy for HER2 normal metastatic breast cancer

This study aimed to evaluate the efficacy of capecitabine monotherapy for patients with human epidermal growth factor receptor-2 (HER2) normal metastatic breast cancer (MBC). The primary endpoint was progression-free survival (PFS), and secondary endpoints included overall survival (OS) and PFS according to treatment line and estrogen receptor (ER) status. Patients who received capecitabine as monotherapy for HER2 normal MBC from 2010 to 2020 were included in this retrospective study. ER status, treatment line, number of treatments, and dates of progression and death were registered. PFS was defined from capecitabine initiation to progression or any cause of death, and OS until any cause of death. Among 162 patients receiving capecitabine, approx. 70% had ER-positive disease. They received a median of six cycles of capecitabine (range 2–45). The median PFS was 4.3 months, with no significant difference between treatment lines. When analyzing PFS according to ER status, a statistically significant difference was observed between those with ER-positive and ER-negative disease, with a median PFS of 5,3 months versus 2,5 months, respectively (p = 0.006). A similar trend was seen for overall survival, with a median OS of 14 months for all patients and 17.8 months versus 7.6 months for patients with ER-positive and ER-negative disease, respectively (p ≤ 0.0001). Patients with HER2 normal MBC receiving monotherapy capecitabine had a median PFS of 4.3 months, and a median OS of 14 months. PFS was consistent regardless of treatment line but differed significantly according to ER status.

Estrogen-receptor status determines differential regulation of α1- and α2-adrenoceptor-mediated cell survival, angiogenesis, and intracellular signaling responses in breast cancer cell lines.

Psychosocial stress promotes cancer pathogenesis involving angiogenesis through alterations in neuroendocrine-immune functions that may involve adrenoceptor (AR)-dependent signaling mechanisms in the brain, lymphoid organs, and cancerous cells. Various concentrations of α1- and α2- AR-specific agonists and antagonists were incubated in vitro with estrogen receptor-positive (ER +) MCF-7, and ER (-) MDA MB-231 cells to examine the secretions of VEGF-A, VEGF-C, and nitric oxide (NO), and expression of signaling molecules- p-ERK, p-CREB, and p-Akt on the proliferation of breast cancer cell lines. Cellular proliferation, VEGF-A and NO secretion, expression of p-ERK, p-CREB, and p-Akt were enhanced in MCF-7 cells treated with α1-AR agonist while VEGF-C secretion alone was enhanced in MDA MB-231 cells. Treatment of MCF-7 and MDA MB-231 cells with α2- AR agonist similarly enhanced proliferation and decreased NO production and p-CREB expression while VEGF-C secretion was decreased in MCF-7 cells and p-Akt expression was decreased in MDA MB-231 cells. α1-AR inhibition reversed cellular proliferation and VEGF-A secretion by MCF-7 cells while α2-AR inhibition reversed the proliferation of MCF-7 and MDA MB-231 cells and VEGF-C secretion by MCF-7 cells. Taken together, breast cancer pathogenesis may be influenced by distinct α-AR-mediated signaling mechanisms on angiogenesis and lymphangiogenesis that are dependent on estrogen receptor status.

Abstract 5403: Meeting the Physical Activity Guidelines is associated with increased CD8+ T-cell density in the tumor microenvironment of breast cancer patients

Abstract Background: Our current understanding of how physical activity (PA) is associated with immunity in breast cancer (BC) patients is based on pre-clinical evidence gleaned from mouse models or immune cells in the circulating blood, which may not be reflective of the tumor immune microenvironment (TIME). Whether self-reported PA is associated with immune cell infiltration in the breast TIME, the most relevant site for prognosis, remains a fundamental gap in knowledge. Herein, we examined the association of self-reported PA in the year before BC diagnosis with CD8+ T-cell density in the breast TIME. As prior evidence from healthy adults suggests the relationship between exercise and immunity is not linear, we hypothesized that patients reporting the highest PA level would not have the highest CD8+ T-cell density in their tumor. Methods: We leveraged data and tumor samples from 685 women with BC (548 self-identified Black and 137 self-identified White) enrolled in the Women’s Circle of Health Study and the Women’s Circle of Health Follow-Up Study. CD8+ T-cell density per square millimeter of tumor tissue was derived from IHC staining of tissue microarrays. Weekly PA in the year before diagnosis was categorized as inactive; low active (&amp;lt;7.5 MET hours/week); moderately active [7.5-14.9 MET hours/week, the equivalent of meeting the minimum PA Guidelines (PAG)]; or high active (≥15.0 MET-hours/week, exceeding the minimum PAG). Log transformed mean CD8+ T-cell densities were compared by PA level using t-tests and multivariable linear regression with adjustment for age, race, estrogen receptor status, and tumor grade. Results: Meeting the minimum PA Guidelines was associated with significantly higher CD8+ T-cell density in the breast TIME [120.4 (353.6)] in comparison to inactivity [62.0 (154.5), p=0.02]. Although there were also distinct differences in T-cell density between moderate and low-active patients [120.4 (353.6) versus 69.5 (172.6), p=0.10] and moderate and high-active patients [120.4 (353.6) versus 80.7 (223.3), p=0.051], associations were shy of significance. Multivariable linear regression analyses confirmed that moderately active patients had significantly higher CD8+ T-cell density in comparison to inactive patients, overall (p=0.029), and among Black patients (p=0.021). Conclusions: In comparison to inactivity, BC patients meeting the PAG (moderate activity) had significantly increased CD8+ T-cell density in their tumor, which is associated with better survival outcomes. This new translational knowledge suggests exercise-induced immunomodulation may be an important molecular mechanism underlying the association of PA with improved BC survival. As the immune system is a key player in treatment response and efficacy, further study of the role that PA ancillary to therapy may play in improving treatment and survival outcomes is warranted. Citation Format: Rikki Cannioto, Angela Omilian, Evan Davis, Lucas Mendicino, Scott Abrams, Bo Qin, Chi-Chen Hong, Elisa Bandera, Song Yao, Christine Ambrosone. Meeting the Physical Activity Guidelines is associated with increased CD8+ T-cell density in the tumor microenvironment of breast cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5403.

Abstract 7321: Second primary cancer risks following breast cancer in BRCA1/2 pathogenic variant carriers

Abstract Background: Second primary cancer (SPC) risk estimates in breast cancer (BC) survivors carrying germline BRCA1/2 pathogenic variants (PVs) remain uncertain. We estimated relative and absolute SPC risks following BC in BRCA1/2 PV carriers using genetic testing laboratory data in England, linked for the first time to population-scale electronic health records data from the National Disease Registration Service and Hospital Episode Statistics. Material and methods: The cohort contained 27,154 women diagnosed with primary BC and tested for germline BRCA1/2 PVs between 1995-2019. Follow-up began at the latest of the genetic test dates and one year following the BC diagnosis and continued until the first SPC diagnosis, death, migration, relevant surgery, and the end of 2020, whichever came first. We estimated overall and site-specific standardized incidence ratios (SIRs) by comparing observed and expected SPC counts, with expected counts calculated using incidences for the general English population accounting for calendar year, SPC site, age, and gender. We stratified the SIRs by age, estrogen-receptor status, and cancer site. We further assessed associations using Cox regression adjusted for age at BC diagnosis and estrogen-receptor status of the first BC, and estimated 10-year absolute SPC risks with Kaplan-Meier analysis. Results: There were 1909 BRCA1 (138 with SPCs) and 1926 BRCA2 (101 with SPCs) PV carriers, with mean follow-up lengths of 4.2 and 4.4y and median follow-up lengths of 3.4 and 3.6y. In BRCA1 PV carriers, there were elevated contralateral BC (SIR:15.3, 95%CI:11.5-19.8), ovarian (SIR:43.3, 95%CI:30.9-58.9), non-breast and non-ovarian combined (SIR:2.23, 95%CI:1.63-2.98), colorectal (SIR:4.72, 95%CI:2.58-7.92) and uterine (SIR:3.42, 95%CI:1.25-7.44) SPC risks. In BRCA2 PV carriers, there were increased contralateral BC (SIR:7.53, 95%CI:5.33-10.3), ovarian (SIR:16.5, 95%CI:10.1-25.5), non-breast and non-ovarian (SIR:1.72, 95%CI:1.27-2.27) and pancreatic (SIR:6.57, 95%CI:2.63-13.5) SPC risks. Consistently, when we compared BC survivors carrying a BRCA1 PV to BC survivors without a PV in either gene, they were at elevated contralateral BC (HR:3.94, 95%CI:2.91-5.33), ovarian (HR:35.7, 95%CI:21.3-60.0), non-breast and non-ovarian (HR:1.53, 95%CI:1.11-2.12) and colorectal (HR:2.95, 95%CI:1.56-5.55) SPC risks, whereas BRCA2 PV carriers were at increased contralateral BC (HR:2.59, 95%CI:1.83-3.65), ovarian (HR:12.3, 95%CI:6.93-21.9) and pancreatic (HR:5.32, 95%CI:2.30-12.3) SPC risks. We estimated 10-year cumulative contralateral BC, ovarian, and non-breast and non-ovarian SPC risks of 15%, 6.3%, and 7.8% in BRCA1 PV carriers and 12%, 2.9%, and 6.2% in BRCA2 PV carriers. Conclusions: Cancer risks were increased, at combined and specific sites, following BC in BRCA1/2 PV carriers. These findings could aid the clinical management of BC survivors carrying BRCA1/2 PVs. Citation Format: Isaac Allen, Hend Hassan, Yvonne Walburga, Catherine Huntley, Lucy Loong, Tameera Rahman, Beth Torr, Andrew Bacon, Craig Knott, Sophie Jose, Sally Vernon, Margreet Lüchtenborg, Joanna Pethick, Francesco Santaniello, Shilpi Goel, Sophie Allen, Katrina Lavelle, Fiona McRonald, Diana M. Eccles, Eva Morris, Steven Hardy, Clare Turnbull, Marc Tischkowitz, Paul Pharoah, Antonis C. Antoniou. Second primary cancer risks following breast cancer in BRCA1/2 pathogenic variant carriers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7321.

Abstract 6267: Evaluating estrogen receptor signaling modifications at bone marrow related stiffnesses in metastatic breast cancer

Abstract Bone metastasis is highly prevalent in breast cancer (BC) patients with metastatic disease and can increase the risk of hypercalcemia and pathological fractures. Several studies have evaluated the mechanisms of metastasized BC cells’ involvement in bone destruction, but how the bone marrow (BM) microenvironment contributes to this process remains ambiguous. Recent studies have shown that as BC cells experience increased stiffnesses outside of the primary microenvironment, there is higher expression of epithelial-to-mesenchymal transition (EMT) markers, increased expression of osteolytic proteins, and decreased drug responses. However, these changes have not been evaluated at stiffnesses relative to the BM. Estrogen receptor (ER) status also plays a pivotal role in BC patient survival. Clinical studies have indicated that the majority of ER+ patients with metastatic disease have more incidences of bone metastases compared to ER- patients. There is some evidence that suggests that the physical properties can also affect estrogen receptor signaling at the primary site, however, there is minimal work to establish how the physical factors of the BM can affect ER sensitivity after metastasis. We hypothesize that higher stiffness ranges of the BM can alter the estrogen receptor sensitivity of metastasized tumor cells and increase osteolysis. To analyze this question, we seeded ER+ BC cell lines (MCF7s and T47Ds) on CytoSoft® Rigidity Plates that mimicked the stiffness of the BM (0.5 - 32 kPa). After 2 days in culture, we probed the expression of downstream estrogen signaling factors, GREB1, PGR, and TIFF1, to evaluate estrogen activity using western blot. Our results show an increase in downstream estrogen signaling at higher stiffnesses (32 kPa) compared to lower stiffnesses (0.5 kPa) at the protein level but not at the transcriptional level. In the future, we will analyze factors associated with osteolysis (ITGB3, TGFB-RII, and PTHLH). Additionally, we plan to conduct RNA sequencing to analyze any larger transcriptional changes at different stiffnesses. Overall, this work gives insight into how estrogen signaling changes in the BM compared to the primary site. It will also give us insight into potential therapeutic targets for ER+ BC after metastasis to the bone. Citation Format: Logan Alexander Northcutt, Marjan Rafat, Julie Rhoades. Evaluating estrogen receptor signaling modifications at bone marrow related stiffnesses in metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6267.

Expression- and splicing-based multi-tissue transcriptome-wide association studies identified multiple genes for breast cancer by estrogen-receptor status

BackgroundAlthough several transcriptome-wide association studies (TWASs) have been performed to identify genes associated with overall breast cancer (BC) risk, only a few TWAS have explored the differences in estrogen receptor-positive (ER+) and estrogen receptor-negative (ER-) breast cancer. Additionally, these studies were based on gene expression prediction models trained primarily in breast tissue, and they did not account for alternative splicing of genes.MethodsIn this study, we utilized two approaches to perform multi-tissue TWASs of breast cancer by ER subtype: (1) an expression-based TWAS that combined TWAS signals for each gene across multiple tissues and (2) a splicing-based TWAS that combined TWAS signals of all excised introns for each gene across tissues. To perform this TWAS, we utilized summary statistics for ER + BC from the Breast Cancer Association Consortium (BCAC) and for ER- BC from a meta-analysis of BCAC and the Consortium of Investigators of Modifiers of BRCA1 and BRCA2 (CIMBA).ResultsIn total, we identified 230 genes in 86 loci that were associated with ER + BC and 66 genes in 29 loci that were associated with ER- BC at a Bonferroni threshold of significance. Of these genes, 2 genes associated with ER + BC at the 1q21.1 locus were located at least 1 Mb from published GWAS hits. For several well-studied tumor suppressor genes such as TP53 and CHEK2 which have historically been thought to impact BC risk through rare, penetrant mutations, we discovered that common variants, which modulate gene expression, may additionally contribute to ER + or ER- etiology.ConclusionsOur study comprehensively examined how differences in common variation contribute to molecular differences between ER + and ER- BC and introduces a novel, splicing-based framework that can be used in future TWAS studies.

Risk factors for breast cancer subtypes by race and ethnicity: A scoping review of the literature.

Breast cancer is comprised of distinct molecular subtypes. Studies have reported differences in risk factor associations with breast cancer subtypes, especially by tumor estrogen receptor (ER) status, but their consistency across racial and ethnic populations has not been comprehensively evaluated. We conducted a qualitative, scoping literature review using the Preferred Reporting Items for Systematic Reviews and Meta-analysis, extension for Scoping Reviews to investigate consistencies in associations between 18 breast cancer risk factors (reproductive, anthropometric, lifestyle, and medical history) and risk of ER-defined subtypes in women who self-identify as Asian, Black or African American, Hispanic or Latina, or White. We reviewed publications between January 1, 1990 and July 1, 2022. Etiologic heterogeneity evidence (convincing, suggestive, none, or inconclusive) was determined by expert consensus. Publications per risk factor ranged from 14 (benign breast disease history) to 66 (parity). Publications were most abundant for White women, followed by Asian, Black or African American, and Hispanic or Latina women. Etiologic heterogeneity evidence was strongest for parity, followed by age at first birth, post-menopausal BMI, oral contraceptive use, and estrogen-only and combined menopausal hormone therapy. Evidence was limited for other risk factors. Findings were consistent across racial and ethnic groups, although the strength of evidence varied. The literature supports etiologic heterogeneity by ER for some established risk factors that are consistent across race and ethnicity groups. However, in non-White populations evidence is limited. Larger, more comparable data in diverse populations is needed to better characterize breast cancer etiologic heterogeneity.

Development and Methodological Validation of a Modified Staging System for de Novo Metastatic Breast Cancer

Validation of a new method for prognostication of de novo metastatic breast cancer (dnMBC) to better reflect the heterogenecity of the disease. To perform external methodological validation of the Plichta staging system, a novel prognostic system for de novo metastatic breast cancer (dnMBC). This retrospective cohort study used a multicenter, nationwide, population-based Danish Breast Cancer Group database to validate the new method. Participants were patients with dnMBC diagnosed between 2010 and 2019. Data were analyzed from April to June 2023. A recursive partitioning analysis (RPA) was performed, as demonstrated by Plichta and colleagues, to group patients with similar overall survival (OS) based on clinical factors. The main outcome was to group patients into 4 prognostic groups based on 3-year OS as stage IVa, greater than 70%; stage IVb, 50% to 70%; stage IVc, 25% to less than 50%; or stage IVd, less than 25%. Bootstrapping was applied for 1000 iterations, with final stage assignments based on the most commonly occurring assignment. A total of 1859 women were included with a median (IQR) age of 69 (57-77) years. With a median potential follow-up of 89.9 (95% CI, 86.4-95.1) months and a median OS of 31.7 (95% CI, 29.5-34.1) months, the RPA stratified patients into 10 groups, with organ sites, estrogen receptor status, and human epidermal growth factor receptor 2 status as the key clinical factors. Three-year survival rates ranged from 62% (95% CI, 56%-69%) to 8% (95% CI, 3%-21%), which were further combined into 3 stage groups: IVb, 59.4% (95% CI, 56.2%-62.8%); IVc, 39.4% (95% CI, 36.2%-43.0%); and IVd, 15.4% (95% CI, 11.2%-21.3%) (P < .001). Following bootstrapping, an IVa group emerged, resulting in 4 stage groups with separate 3-year OS rates identified as IVa, 75.8% (95% CI, 67.8%-84.7%); IVb, 58.8% (95% CI, 55.5%-62.3%); IVc, 39.2% (95% CI, 35.8%-43.0%); and IVd, 14.4% (95% CI, 10.8%-19.4%) (P < .001). These findings provide external and independent validation of the methods applied in the novel Plichta staging system for dnMBC. This could guide future revisions of the current American Joint Committee on Cancer staging guidelines and may be incorporated as a stratification factor in clinical trials.