Estrogen/progesterone receptor and HER2 discordance between primary tumor and brain metastases in breast cancer and its effect on treatment and survival

Abstract Background Breast cancer treatment is based on estrogen receptors (ERs), progesterone receptors (PRs), and human epidermal growth factor receptor 2 (HER2). At the time of metastasis, receptor status can be discordant from that at initial diagnosis. The purpose of this study was to determine the incidence of discordance and its effect on survival and subsequent treatment in patients with breast cancer brain metastases (BCBM). Methods A retrospective database of 316 patients who underwent craniotomy for BCBM between 2006 and 2017 was created. Discordance was considered present if the ER, PR, or HER2 status differed between the primary tumor and the BCBM. Results The overall receptor discordance rate was 132/316 (42%), and the subtype discordance rate was 100/316 (32%). Hormone receptors (HR, either ER or PR) were gained in 40/160 (25%) patients with HR-negative primary tumors. HER2 was gained in 22/173 (13%) patients with HER2-negative primary tumors. Subsequent treatment was not adjusted for most patients who gained receptors—nonetheless, median survival (MS) improved but did not reach statistical significance (HR, 17–28 mo, P = 0.12; HER2, 15–19 mo, P = 0.39). MS for patients who lost receptors was worse (HR, 27–18 mo, P = 0.02; HER2, 30–18 mo, P = 0.08). Conclusions Receptor discordance between primary tumor and BCBM is common, adversely affects survival if receptors are lost, and represents a missed opportunity for use of effective treatments if receptors are gained. Receptor analysis of BCBM is indicated when clinically appropriate. Treatment should be adjusted accordingly. Key Points 1. Receptor discordance alters subtype in 32% of BCBM patients. 2. The frequency of receptor gain for HR and HER2 was 25% and 13%, respectively. 3. If receptors are lost, survival suffers. If receptors are gained, consider targeted treatment.

Download Full-text

Subtype switching in breast cancer brain metastases: a multicenter analysis

Neuro-Oncology ◽

10.1093/neuonc/noaa013 ◽

2020 ◽

Vol 22 (8) ◽

pp. 1173-1181 ◽

Cited By ~ 8

Author(s):

Alexander F C Hulsbergen ◽

An Claes ◽

Vasileios K Kavouridis ◽

Ali Ansaripour ◽

Claudine Nogarede ◽

...

Keyword(s):

Breast Cancer ◽

Brain Metastases ◽

Growth Factor Receptor ◽

Hazard Ratio ◽

Receptor Expression ◽

Her2 Status ◽

Primary Tumors ◽

Pathology Reports ◽

Breast Cancer Brain Metastases ◽

Extracranial Metastases

Abstract Background Breast cancer (BC) brain metastases (BM) can have discordant hormonal or human epidermal growth factor receptor 2 (HER2) expression compared with corresponding primary tumors. This study aimed to describe incidence, predictors, and survival outcomes of discordant receptors and associated subtype switching in BM. Methods BCBM patients seen at 4 tertiary institutions who had undergone BM resection or biopsy were included. Surgical pathology reports were retrospectively assessed to determine discordance between the primary tumor and the BCBM. In discordant cases, expression in extracranial metastases was also assessed. Results In BM from 219 patients, prevalence of any discordance was 36.3%; receptor-specific discordance was 16.7% for estrogen, 25.2% for progesterone, and 10.4% for HER2. Because estrogen and progesterone were considered together for hormonal status, 50 (22.8%) patients switched subtype as a result; 20 of these switches were HER2 based. Baseline subtype predicted switching, which occurred in up to 37.5% of primary HR+ patients. Moreover, 14.8% of initially HER2-negative patients gained HER2 in the BM. Most (63.6%) discordant patients with extracranial metastases also had discordance between BM and extracranial subtype. Loss of receptor expression was generally associated with worse survival, which appeared to be driven by estrogen loss (hazard ratio = 1.80, P = 0.03). Patients gaining HER2 status (n = 8) showed a nonsignificant tendency toward improved survival (hazard ratio = 0.64, P = 0.17). Conclusions In this multicenter study, we report incidence and predictors of subtype switching, the risk of which varies considerably by baseline subtype. Switches can have clinical implications for prognosis and treatment choice.

Download Full-text

Prospective Study Evaluating the Impact of Tissue Confirmation of Metastatic Disease in Patients With Breast Cancer

Journal of Clinical Oncology ◽

10.1200/jco.2010.33.5232 ◽

2012 ◽

Vol 30 (6) ◽

pp. 587-592 ◽

Cited By ~ 256

Author(s):

Eitan Amir ◽

Naomi Miller ◽

William Geddie ◽

Orit Freedman ◽

Farrah Kassam ◽

...

Keyword(s):

Breast Cancer ◽

Prospective Study ◽

Treatment Plan ◽

Growth Factor Receptor ◽

Metastatic Breast ◽

Her2 Status ◽

Primary Tumors ◽

Receptor Status ◽

Metastatic Recurrence ◽

The Impact

Purpose Decisions about treatment for women with metastatic breast cancer are usually based on the estrogen (ER), progesterone (PgR), and human epidermal growth factor receptor 2 (HER2) status of the primary tumor. Retrospective data suggest that discordance between primary and metastatic lesions leads to detrimental outcome. This prospective study investigated receptor status of primary tumors and metastases in the same patient and assessed the impact of discordance on patient management and survival. Patients and Methods Biopsies of suspected metastases were analyzed for ER, PgR, and HER2. Primary tumors and metastases were analyzed using similar methodology. The treating oncologist indicated a treatment plan before and after biopsy to determine whether the result influenced management. Patients were followed up for progression or death. Results Of 121 women undergoing biopsy, 80% could be analyzed for receptor status. Discordance in ER, PgR, and HER2 between the primary and the metastasis was 16%, 40%, and 10%, respectively. Biopsy led to a reported change of management in 14% of women (95% CI, 8.4% to 21.5%). Fine-needle aspiration and biopsy of bone led to reduced ability to analyze receptors. After a median follow-up of 12 months, there were no trends for an association between receptor discordance and either time to treatment failure or overall survival. Conclusion Biopsy of metastases is technically feasible. Clinicians alter immediate management in one of seven patients on the basis of results of the biopsy, and discordance is not then associated with detrimental effects on outcome. Tissue confirmation should be considered in women with breast cancer and suspected metastatic recurrence.

Download Full-text

33. SYSTEMATIC REVIEW AND META-ANALYSIS OF BREAST CANCER BRAIN METASTASIS AND PRIMARY TUMOR RECEPTOR EXPRESSION DISCORDANCE

Neuro-Oncology Advances ◽

10.1093/noajnl/vdaa073.021 ◽

2020 ◽

Vol 2 (Supplement_2) ◽

pp. ii6-ii6

Author(s):

Rupesh Kotecha ◽

Raees Tonse ◽

Muni Rubens ◽

Michael McDermott ◽

Yazmin Odia ◽

...

Keyword(s):

Breast Cancer ◽

Systematic Review ◽

Brain Metastasis ◽

Primary Tumor ◽

Expression Profiles ◽

Receptor Expression ◽

Her2 Status ◽

Tumor Subtype ◽

Primary Tumors ◽

Breast Cancer Brain Metastasis

Abstract BACKGROUND Discordance in hormone receptor (estrogen [ER] and progesterone [PR]) and human epidermal growth factor receptor2 (HER2) status between the primary tumor and brain metastases and its effect on tumor classification subtype switching has been described but remains understudied. METHODS Using the PRISMA guidelines, a systematic review was performed of series published prior to April 2020 of biopsied or resected breast cancer brain metastasis (BCBM) from the Medline database using the keywords “breast cancer” and “brain metastasis” combined with “estrogen receptor/ER,” “progesterone receptor/PR,” “HER2/neu,” and “receptor conversion/dis- or concordance.” Weighted random effects models were used to calculate pooled estimates. RESULTS Fifteen full-text articles met inclusion criteria and cumulatively reported on 1373 patients who underwent biopsy or resection of at least one BCBM to compare to their primary tumor. At initial diagnosis, receptor expression profiles were 45.0% ER+, 41.0% ER-, 31.0% PR+, 51.0% PR-, 35% HER2+, and 47.0% HER2-. Corresponding receptor expression profiles from the BCBM were 19.0% ER+, 31.0% ER-, 13.0% PR+, 40.0% PR-, 21.0% HER2+, and 26.0% HER2-. Intra-patient receptor discordance comparisons revealed that 540 patients (42.6%) exhibited discordance in any receptor with 17.0% (95% CI: 13.0%-23.0%) discordance for ER status, 23.0% (95% CI: 18.0%-30.0%) for PR status, and 12.0% (95% CI: 8.0%-16.0%) for HER2 status. The most common receptor discordance events found in BCBM compared to primary tumors were ER loss 11.0% (95% CI: 8.0%-16.0%), PR loss 15.0% (95% CI: 11.0%-21.0%), and HER2 gain 9.0% (95% CI: 7.0%-11.0%). CONCLUSIONS BCBM commonly exhibit receptor expression changes on comparison to primary tumors including a 10% HER2 gain rate, a potential actionable target. Classification patterns need to be updated to reflect changes in overall tumor subtype grouping and which factors predict for BCBM/primary tumor discordance. Overall, tumor subtype switching and its effect on clinical management remains underappreciated.

Download Full-text

HER2 antibody-drug conjugate controls growth of breast cancer brain metastases in hematogenous xenograft models, with heterogeneous blood–tumor barrier penetration unlinked to a passive marker

Neuro-Oncology ◽

10.1093/neuonc/noaa118 ◽

2020 ◽

Vol 22 (11) ◽

pp. 1625-1636 ◽

Cited By ~ 1

Author(s):

Brunilde Gril ◽

Debbie Wei ◽

Alexandra S Zimmer ◽

Christina Robinson ◽

Imran Khan ◽

...

Keyword(s):

Breast Cancer ◽

Brain Metastasis ◽

Brain Metastases ◽

Statistical Significance ◽

Growth Factor Receptor ◽

Antibody Drug Conjugate ◽

Brain Penetration ◽

Her2 Breast Cancer ◽

Antibody Drug

Abstract Background Brain metastases of HER2+ breast cancer persist as a clinical challenge. Many therapeutics directed at human epidermal growth factor receptor 2 (HER2) are antibodies or antibody-drug conjugates (ADCs), and their permeability through the blood–tumor barrier (BTB) is poorly understood. We investigated the efficacy of a biparatopic anti-HER2 antibody-tubulysin conjugate (bHER2-ATC) in preclinical models of brain metastases. Methods The compound was evaluated in 2 hematogenous HER2+ brain metastasis mouse models, SUM190-BR and JIMT-1-BR. Endpoints included metastasis count, compound brain penetration, cancer cell proliferation, and apoptosis. Results Biparatopic HER2-ATC 3 mg/kg prevented metastasis outgrowth in the JIMT-1-BR model. At 1 mg/kg bHER2-ATC, a 70% and 92% reduction in large and micrometastases was observed. For the SUM190-BR model, an 85% and 53% reduction, respectively, in large and micrometastases was observed at 3 mg/kg, without statistical significance. Proliferation was reduced in both models at the highest dose. At the endpoint, bHER2-ATC uptake covered a median of 4–6% and 7–17% of metastasis area in the JIMT-1-BR and SUM190-BR models, respectively. Maximal compound uptake in the models was 19% and 86% in JIMT-1-BR and SUM190-BR, respectively. Multiple lesions in both models demonstrated ADC uptake in the absence or low diffusion of Texas Red Dextran, a marker of paracellular permeability. Using in vitro BTB assays, the ADC was endocytosed into brain endothelial cells, identifying a potentially new mechanism of antibody permeability. Conclusions Biparatopic HER2-ATC significantly prevented JIMT-1-BR brain metastasis outgrowth and showed activity in the SUM190-BR model. The bHER2-ATC penetration into metastases that are impermeable to fluorescent dye suggested an endocytic mechanism of brain penetration.

Download Full-text

Number of tumor-infiltrating lymphocytes in breast cancer brain metastases compared to matched breast primaries.

Journal of Clinical Oncology ◽

10.1200/jco.2017.35.15_suppl.2049 ◽

2017 ◽

Vol 35 (15_suppl) ◽

pp. 2049-2049 ◽

Cited By ~ 1

Author(s):

Jessie Narloch ◽

Catherine Luedke ◽

Gloria Broadwater ◽

Nolan Priedigkeit ◽

Allison Hall ◽

...

Keyword(s):

Breast Cancer ◽

Brain Metastasis ◽

Brain Metastases ◽

Tumor Infiltrating Lymphocytes ◽

Cox Proportional Hazards Model ◽

Her2 Status ◽

Primary Tumors ◽

Metastatic Setting ◽

Breast Cancer Brain Metastasis ◽

Infiltrating Lymphocytes

2049 Background: Breast cancer brain metastasis (BCBM) is frequent in advanced disease, has limited therapies, and is associated with poor prognosis. Increased stromal tumor infiltrating lymphocytes (sTILs) are prognostic in triple-negative breast cancer (TNBC) and predictive of therapeutic response in early breast cancer (BC). However, little is known about sTILs in the metastatic setting. We compared %sTILs between the largest known cohort of matched primary tumors and BCBM and correlated the results with clinical endpoints. Methods: We retrospectively investigated 37 matched primary tumors and BCBM tissue from three institutions. In addition, we identified 29 primary tumors from patients later diagnosed with BCBM. H&E-stained sections were manually measured for %sTILs using standard criteria. Wilcoxon signed rank tests assessed for changes in %sTILs between primary and metastatic lesions. A Cox proportional hazards model was used to determine if %sTILs in the breast tissue predicts time from primary tumor biopsy to diagnosis of brain metastasis (TTDBM) while adjusting for clinicopathologic features. Results: Average age at time of BCBM diagnosis was 53.6 (SD 12.3). 52% (34/66) of primary tumors were hormone receptor (HR) positive. Of 60 patients with known HER2 status, 28% (17) were HER2 positive and 40% (24) TNBC. Median %sTILS was significantly different between all primary tumors (15, IQR 5-20) and brain metastases (10, IQR 5-10), p = 0.001. The TNBC subtype (n = 11) showed the largest decrease in %sTILs between primary tumors (20, IQR 10-20) and brain metastases (5, IQR 5-10), p = 0.022. Comparing primary tumors and brain metastases, there was a 5% decrease in %sTILs in HR-/HER2+ (n = 5, p = 0.13) and HR+/HER2- (n = 7, p = 0.13), and a 5% increase in %sTILs in the HR+/Her2+ subtype (n = 9, p = 0.69). Percent sTILs in the primary tumors was not a significant predictor of TTDBM, when adjusting for race, age, HR status, and HER2 status, p = 0.87. Conclusions: BCBM have a significantly decreased %sTILs compared to their primary tumors, most prominent in TNBC. These results suggest altered tumor immunogenicity in the metastatic setting which has broad implications for the development of immunotherapy.

Download Full-text

Biomarkers Changes after Neoadjuvant Chemotherapy in Breast Cancer: A Seven-Year Single Institution Experience

Diagnostics ◽

10.3390/diagnostics11122249 ◽

2021 ◽

Vol 11 (12) ◽

pp. 2249

Author(s):

Saverio Coiro ◽

Elisa Gasparini ◽

Giuseppe Falco ◽

Giacomo Santandrea ◽

Moira Foroni ◽

...

Keyword(s):

Breast Cancer ◽

Neoadjuvant Chemotherapy ◽

Hormone Receptors ◽

Growth Factor Receptor ◽

Progesterone Receptors ◽

Residual Tumor ◽

Intrinsic Subtype ◽

Her2 Status ◽

Epidermal Growth ◽

Prognostic Implications

The adoption of neoadjuvant chemotherapy (NACT) for breast cancer (BC) is increasing. The need to repeat the biomarkers on a residual tumor after NACT is still a matter of debate. We verified estrogen receptors (ER), progesterone receptors (PR), Ki67 and human epidermal growth factor receptor 2 (HER2) status changes impact in a retrospective monocentric series of 265 BCs undergoing NACT. All biomarkers changed with an overall tendency toward a reduced expression. Changes in PR and Ki67 were statistically significant (p = 0.001). Ki67 changed in 114/265 (43.0%) cases, PR in 44/265 (16.6%), ER in 31/265 (11.7%) and HER2 in 26/265 (9.8%). Overall, intrinsic subtype changed in 72/265 (27.2%) cases after NACT, and 10/265 (3.8%) cases switched to a different adjuvant therapy accordingly. Luminal subtypes changed most frequently (66/175; 31.7%) but with less impact on therapy (5/175; 2.8%). Only 3 of 58 triple-negative BCs (5.2%) changed their intrinsic subtype, but all of them switched treatment. No correlation was found between intrinsic subtype changes and clinicopathological features. To conclude, biomarkers changes with prognostic implications occurred in all BC intrinsic subtypes, albeit they impacted therapy mostly in HER2 negative and/or hormone receptors negative BCs. Biomarkers retesting after NACT is important to improve both tailored adjuvant therapies and prognostication of patients.

Download Full-text

Correlation of levels of Akt phosphorylation at Ser473 with benefit from paclitaxel chemotherapy in NSABP B-28 patients with node-positive breast cancer

Journal of Clinical Oncology ◽

10.1200/jco.2009.27.15_suppl.537 ◽

2009 ◽

Vol 27 (15_suppl) ◽

pp. 537-537

Author(s):

S. X. Yang ◽

J. P. Costantino ◽

D. Nguyen ◽

J. Jeong ◽

E. P. Mamounas ◽

...

Keyword(s):

Breast Cancer ◽

Clinical Outcome ◽

Imaging System ◽

Statistical Significance ◽

Her2 Status ◽

Primary Tumors ◽

Akt Phosphorylation ◽

Node Positive ◽

Sequential Addition ◽

Positive Breast Cancer

537 Background: We investigated the levels of tumor phospho-Akt(Ser473) (pAkt) and treatment outcome of patients with node-positive breast cancer after adjuvant treatment with doxorubicin/cyclophosphamide (AC) followed by four cycles of paclitaxel (PTX) (AC→PTX) compared with AC chemotherapy alone in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-28 trial. Methods: The primary tumors on B-28 tissue microarray were available from 1581 of 3060 patients enrolled. pAkt status was examined by immunohistochemistry with the antibody to pAkt(Ser473) (Cell Signaling Technology) at the National Cancer Institute. Levels of pAkt were quantitatively scored with the assistance of an Automated Digital Imaging System blinded to clinical outcome, and categorized by the staining index (intensity X % of staining /100) of > 2 (high) and ≤ 2 (low). The association between tumor pAkt level and clinical outcome at 10 years was assessed using multivariate Cox modeling adjusting for age, tumor size, number of positive nodes, tumor grade, estrogen receptor and HER2 status. Results: Among patients with low tumor pAkt levels (n = 975), there was no DFS difference between those treated with or without PTX (adjusted HR = 1.02, p = 0.81). However, among patients with high tumor pAkt levels (n = 606), those treated with AC→PTX had a 26% reduction in DFS event rate compared to those treated with AC only (adjusted HR = 0.74, p = 0.02). There was no OS difference between treatment groups for those with low pAkt cancer (HR = 0.97, p = 0.80). In patients with high pAkt cancer, those treated with AC→PTX had a 20% reduction in death rate compared to those treated with AC only but this difference did not reach statistical significance (adjusted HR = 0.80, p = 0.17). Conclusions: High levels of Akt phosphorylation at Ser473 independently predict a DFS benefit from the sequential addition of paclitaxel to adjuvant doxorubicin plus cyclophosphamide in node-positive breast cancer. Patients with low levels of pAkt breast cancer may not benefit from the sequential addition of PTX to doxorubicin plus cyclophosphamide. [Table: see text]

Download Full-text

Discordance in Human Epidermal Growth Factor Receptor 2 (HER2) Phenotype Between Primary Tumor and Circulating Tumor Cells in Women With HER2-Negative Metastatic Breast Cancer

JCO Precision Oncology ◽

10.1200/po.17.00023 ◽

2017 ◽

pp. 1-12 ◽

Cited By ~ 3

Author(s):

Amelie De Gregorio ◽

Thomas W.P. Friedl ◽

Jens Huober ◽

Christoph Scholz ◽

Nikolaus De Gregorio ◽

...

Keyword(s):

Breast Cancer ◽

Metastatic Breast Cancer ◽

Primary Tumor ◽

Tumor Heterogeneity ◽

Growth Factor Receptor ◽

Metastatic Breast ◽

Hormone Receptor Status ◽

Her2 Status ◽

Histologic Type ◽

Epidermal Growth

Purpose Discordance in human epidermal growth factor receptor 2 (HER2) status between primary tumor and metastases might have important implications for treatment response and therapy decisions. Here, we evaluate both the frequency of circulating tumor cells (CTCs) and the factors predicting HER2 discordance between primary tumor and CTCs as a potential surrogate for tumor biology and tumor heterogeneity in patients with metastatic breast cancer. Patients and Methods The number of CTCs in 7.5 mL of peripheral blood and HER2 status were evaluated in 1,123 women with HER2-negative metastatic breast cancer. HER2 discordance was defined as the presence of at least one CTC with a strong immunocytochemical HER2 staining intensity. Factors predicting discordance in HER2 phenotype were assessed using multivariable logistic regression. Results Overall, 711 (63.3%) of 1,123 screened patients were positive for CTCs (≥ one CTC). Discordance in HER2 phenotype between primary tumor and CTCs was observed in 134 patients (18.8%) and was significantly associated with histologic type (lobular v ductal; odds ratio [OR], 2.67; 95% CI, 1.63 to 4.39; P < .001), hormone receptor status (positive v negative; OR, 2.84; 95% CI, 1.15 to 7.02; P = .024), and CTC number (≥ five v one to four; OR, 7.64; 95% CI, 3.97 to 14.72; P < .001). Conclusion HER2 discordance between primary tumor and CTCs was observed in 18.8% of patients and was associated with histologic type, hormone receptor status of the primary tumor, and CTC number. The clinical utility of CTCs as liquid biopsy to assess tumor heterogeneity of metastatic disease and guide treatment decisions must be evaluated in prospective randomized trials.

Download Full-text

CMET-29. HORMONE RECEPTORS STATUS: A STRONG DETERMINANT OF THE KINETICS OF BRAIN METASTASES OCCURRENCE COMPARED WITH HER2 STATUS IN BREAST CANCER

Neuro-Oncology ◽

10.1093/neuonc/nox168.176 ◽

2017 ◽

Vol 19 (suppl_6) ◽

pp. vi45-vi45

Author(s):

Amélie Darlix ◽

Gaia Griguolo ◽

Simon Thezenas ◽

Eva Kantelhardt ◽

Christoph Thomssen ◽

...

Keyword(s):

Breast Cancer ◽

Brain Metastases ◽

Hormone Receptors ◽

Her2 Status ◽

Kinetics Of

Download Full-text

Expression of hormone receptors ERα, ERβ and PgR in HER2-positive breast cancers

Journal of Clinical Oncology ◽

10.1200/jco.2006.24.18_suppl.10525 ◽

2006 ◽

Vol 24 (18_suppl) ◽

pp. 10525-10525

Author(s):

M. Litwiniuk ◽

V. Filas ◽

J. Moczko ◽

R. Kaleta ◽

J. Breborowicz

Keyword(s):

Breast Cancer ◽

Hormone Receptors ◽

Detection System ◽

Statistical Significance ◽

Her2 Status ◽

Breast Cancers ◽

Breast Cancer Patients ◽

Her2 Positive ◽

Her2 Positive Breast Cancer ◽

Positive Breast Cancer

10525 Background: HER-2/neu gene is amplified and overexpressed in 15–20% of invasive breast cancers. HER2-positive breast cancers have a worse prognosis than HER2-negative tumors and distinctive clinical features. They express hormone receptors for estrogen (ERα) and for progesterone (PgR) less frequently than HER2-negative tumors. The identification of the other human estrogen receptor, receptor beta (ERβ), raises a question of ERβ occurrence in HER2-positive breast cancer. Patients and methods: Formalin-fixed, paraffin embedded tissues from 90 patients with invasive HER2-positive breast cancer and from 99 patients with HER2-negative breast cancer were used in this study. The HER2 status was analyzed using HercepTest TM (IHC), and IHC 2+ results were confirmed with FISH test. Immunostaining for ERα, ERβ and PgR was performed using monoclonal antibodies against ERα, PgR (DakoCytomation) and against ERβ (CHEMICON). The EnVision detection system was applied. The data were analyzed using nonparametric Fisher-Freeman-Halton test; the statistical significance was considered when p < 0.5. Results: Only 33% of the HER2-positive breast cancers were ERα-positive compared with 63% in the HER2-negative group (p < 0.001). The expression of ERβ protein was observed in almost equal frequency in both groups (57% of HER2-positive breast cancers and 57.7% of HER2-negative tumors, p = 0.889). The expression of PgR was observed in 30% of HER2-positive breast cancers and in 68.7% of HER2-negative tumors (p < 0.001). Conclusion: The expression of ERβ (unlike that of ERα and PgR) was similar in HER2-positive and in HER2-negative breast cancers. Thus, ERβ may be a potential target in future endocrine therapy for women with HER2-positive breast cancers. No significant financial relationships to disclose.

Download Full-text