Androgen Receptor Expression in an Indian Breast Cancer Cohort with Relation to Molecular Subtypes and Response to Neoadjuvant Chemotherapy - a Prospective Clinical Study

An androgen receptor regulated gene score is associated with epithelial to mesenchymal transition features in triple negative breast cancers

BACKGROUND

Androgen receptor (AR) is considered a marker of better prognosis in hormone receptor positive breast cancers (BC), however, its role in triple negative breast cancer (TNBC) is controversial. This may be attributed to intrinsic molecular differences or scoring methods for AR positivity. We derived AR regulated gene score and examined its utility in BC subtypes.

METHODS

AR regulated genes were derived by applying a bioinformatic pipeline on publicly available microarray data sets of AR+ BC cell lines and gene score was calculated as average expression of six AR regulated genes. Tumors were divided into AR high and low based on gene score and associations with clinical parameters, circulating androgens, survival and epithelial to mesenchymal transition (EMT) markers were examined, further evaluated in invitro models and public datasets.

RESULTS

53% (133/249) tumors were classified as AR gene score high and were associated with significantly better clinical parameters, disease-free survival (86.13 vs 72.69 months, log rank p = 0.032) when compared to AR low tumors. 36% of TNBC (N = 66) were AR gene score high with higher expression of EMT markers (p = 0.024) and had high intratumoral levels of 5α-reductase, enzyme involved in intracrine androgen metabolism. In MDA-MB-453 treated with dihydrotestosterone, SLUG expression increased, E-cadherin decreased with increase in migration and these changes were reversed with bicalutamide. Similar results were obtained in public datasets.

CONCLUSION

Deciphering the role of AR in BC is difficult based on AR protein levels alone. Our results support the context dependent function of AR in driving better prognosis in ER positive tumors and EMT features in TNBC tumors.

Prognostic value of androgen receptor expression in different molecular types of breast cancer in women

BACKGROUND

Breast cancer is a common women's disease. Usually, oestrogen is blamed in the aetiology and correlated with the prognosis; however, androgens are recently raising concern about its role in the breast cancer treatment and prognosis.

METHODS

In this study we retrieved archival paraffin blocks of breast cancer patients and stained it for androgen. Thereafter, we compared clinico-epidemiologic parameters, histopathology, neoadjuvant response and recurrence rate and pattern among patients with and without androgen receptor (AR) expression.

RESULTS

In total, 119 patients fulfilled enrolment criteria; AR expression were present in 77.3% of the patients. AR expression was associated with less grade III (6.8% versus 36.4%), and less triple negative (6.2% versus 25%), but similar overall recurrence rate (25% versus 22.2%). However, distant recurrence was significantly higher in androgen positive patients (91.3% versus 33.3% of all recurrences).

CONCLUSION

Androgen expression appears to be common among breast cancer, but with no clear implication in tumour aggressiveness or effect on the rate of recurrence. However, being commonly associated with distant spread may have an impact on survival of the patients.

Cysteine conjugate beta-lyase 2 (CCBL2) expression as a prognostic marker of survival in breast cancer patients

Objective

Cysteine conjugate beta-lyase 2 (CCBL2), also known as kynurenine aminotransferase 3 (KAT3) or glutamine transaminase L (GTL), plays an essential role in transamination and cytochrome P450. Its correlation with some other cancers has been explored, but breast cancer (BC) not yet.

Methods

The mRNA and protein expression of CCBL2 in BC cell lines and patient samples were detected by RT-qPCR and immunohistochemistry (IHC). BC patients’ clinical information and RNA-Seq expression were acquired via The Cancer Genome Atlas (TCGA) database. Patients were categorized into high/low CCBL2 expression groups based on the optimal cutoff value (8.973) determined by receiver operating characteristic (ROC) curve. We investigated CCBL2 and clinicopathological characteristics’ relationship using Chi-square tests, estimated diagnostic capacity using ROC curves and drew survival curves using Kaplan–Meier estimate. We compared survival differences using Cox regression and externally validated using Gene Expression Omnibus (GEO) database. We evaluated enriched signaling pathways using gene set enrichment analysis (GSEA), explored CCBL2 and relevant genes’ relationship using tumor immunoassay resource (TIMER) databases and used the human protein atlas (HPA) for pan-cancer analysis and IHC.

Results

CCBL2 was overexpressed in normal human cell lines and tissues. CCBL2 expression was lower in BC tissues (n = 1104) than in normal tissues (n = 114), validated by GEO database. Several clinicopathologic features were related to CCBL2, especially estrogen receptor (ER), progesterone receptor (PR) and clinical stages. The low expression group exhibited poor survival. CCBL2’s area under curve (AUC) analysis showed finite diagnostic capacity. Multivariate cox-regression analysis indicated CCBL2 independently predicted BC survival. GSEA showed enriched pathways: early estrogen response, MYC and so on. CCBL2 positively correlated with estrogen, progesterone and androgen receptors. CCBL2 was downregulated in most cancers and was associated with their survival, including renal and ovarian cancers.

Conclusions

Low CCBL2 expression is a promising poor BC survival independent prognostic marker.

Androgen Receptor: A New Marker to Predict Pathological Complete Response in HER2-Positive Breast Cancer Patients Treated with Trastuzumab Plus Pertuzumab Neoadjuvant Therapy

(1) Background: Neoadjuvant therapy is the main therapeutic strategy for human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients, and the combination of trastuzumab and pertuzumab (HP) has become a routine treatment. How to predict and screen patients who are less likely to respond to neoadjuvant therapy is the focus of research. The androgen receptor (AR) is a biomarker that is widely expressed in all breast cancer subtypes and is probably related to treatment response and prognosis. In this study, we investigated the relationship between AR expression and treatment response in HER2-positive breast cancer patients treated with HP neoadjuvant therapy. (2) Methods: We evaluated early breast cancer patients treated with HP neoadjuvant therapy from Jan. 2019 to Oct. 2020 at Peking University First Hospital Breast Cancer Center. The inclusion criteria were as follows: early HER2-positive breast cancer patients diagnosed by core needle biopsy who underwent both HP neoadjuvant therapy and surgery. We compared the clinical and pathological features between pathological complete response (pCR) and non-pCR patients. (3) Results: We included 44 patients. A total of 90.9% of patients received neoadjuvant therapy of taxanes, carboplatin, trastuzumab and pertuzumab (TCHP), and the total pCR rate was 50%. pCR was negatively related to estrogen receptor (ER) positivity (OR 0.075 [95% confidence interval (CI) 0.008–0.678], p = 0.021) and positively related to high expression levels of AR (OR 33.145 [95% CI 2.803–391.900], p = 0.005). We drew a receiver operating characteristic (ROC) curve to assess the predictive value of AR expression for pCR, and the area under the curve was 0.737 (95% CI 0.585–0.889, p = 0.007). The optimal cutoff of AR for predicting pCR was 85%. (4) Conclusion: AR is a potential marker for the prediction of pCR in HER2-positive breast cancer patients treated with HP neoadjuvant therapy.

Impact of Androgen Receptor Expression and the AR:ER Ratio on the Survival Outcomes in the Diverse Subgroups of Vietnamese Breast Cancer: A Single Institutional Retrospective Cohort Analysis

Background: The androgen receptor (AR) has recently emerged as a useful marker for the more favorable prognosis and better outcomes among women with estrogen receptor (ER) + ve breast cancer (BC) and the further refinement of BC subtype. Furthermore, AR expression in ER − ve tumors has a particular prognostic significance. Additionally, the ratio of nuclear AR to ER may critically have an influence on tumor biology and respond to endocrine therapy. Purpose: To define the AR expression and AR:ER ratio, and explored their correlation with the clinicopathological features, prognosis, and survival outcomes in the various subclasses of invasive BC. Methods: The current study was conducted on 522 BC patients who had surgical operations, without neoadjuvant chemotherapy by applying a retrospective cohort analysis. The clinicopathological characteristics were recorded. Immunohistochemical staining was performed on AR, ER, PR, HER2, and Ki67. Expression of AR was paired into different immunophenotypes for analysis with clinicopathological features and survival. All BC patients’ survival was analyzed using Kaplan–Meier and log-rank models. Results: The presence of AR was detected in 65.3%. Positive AR, the ratio of AR:ER<2, luminal androgen receptor (LAR) + and AR + HER2 + immunophenotypes were significantly associated with better prognostic features. AR:ER<2 was observed in the prolonged overall survival (OS) and disease-free survival (DFS) (87.9 and 86.2%, respectively) compared to AR:ER≥2 (25.0% in both) (P < .001). In contrast, in HR + ve BCs, the AR expression was not significantly correlated with survival. The multivariate model revealed that the ratio of nuclear AR to ER remained as an independent prognostic variable. Conclusion: The AR expression had a distinct OS and DFS. The AR:ER ratio is an independent indicator for predicting the OS and DFS of BC patients in both univariate and multivariate analyses.

Pre-Menopausal Women With Breast Cancers Having High AR/ER Ratios in the Context of Higher Circulating Testosterone Tend to Have Poorer Outcomes

Purpose

Women with breast tumors with higher expression of AR are in general known to have better survival outcomes while a high AR/ER ratio is associated with poor outcomes in hormone receptor positive breast cancers mostly in post menopausal women. We have evaluated the AR/ER ratio in the context of circulating androgens specifically in patients younger than 50 years most of whom are pre-menopausal and hence have a high estrogenic hormonal milieu.

Methods

Tumor samples from patients 50 years or younger at first diagnosis were chosen from a larger cohort of 270 patients with median follow-up of 72 months. Expression levels of ER and AR proteins were detected by immunohistochemistry (IHC) and the transcript levels by quantitative PCR. Ciculating levels of total testosterone were estimated from serum samples. A ratio of AR/ER was derived using the transcript levels, and tumors were dichotomized into high and low ratio groups based on the third quartile value. Survival and the prognostic significance of the ratio was compared between the low and high ratio groups in all tumors and also within ER positive tumors. Results were further validated in external datasets (TCGA and METABRIC).

Results

Eighty-eight (32%) patients were ≤50 years, with 22 having high AR/ER ratio calculated using the transcript levels. Circulating levels of total testosterone were higher in women whose tumors had a high AR/ER ratio (p = 0.02). Tumors with high AR/ER ratio had significantly poorer disease-free survival than those with low AR/ER ratio [HR-2.6 (95% CI-1.02-6.59) p = 0.04]. Evaluation of tumors with high AR/ER ratio within ER positive tumors alone reconfirmed the prognostic relevance of the high AR/ER ratio with a significant hazard ratio of 4.6 (95% CI-1.35-15.37, p = 0.01). Similar trends were observed in the TCGA and METABRIC dataset.

Conclusion

Our data in pre-menopausal women with breast cancer suggest that it is not merely the presence or absence of AR expression but the relative activity of ER, as well as the hormonal milieu of the patient that determine clinical outcomes, indicating that both context and interactions ultimately influence tumor behavior.

Wntless (Wls): A Prognostic Index for Progression and Patient Survival of Breast Cancer

Background

Wntless (Wls) is an essential protein that is necessary for the secretion of Wnt proteins. While numerous researches have demonstrated that aberrations in Wnt/β-catenin expression lead to tumorigenesis and progression in many cancer types, the effects of Wls in breast cancer (BC) are less studied.

Methods

The mRNA and protein expression of Wls in BC cell lines were detected by RT-qPCR and Western blot; the protein expression of patient samples was detected by immunohistochemistry (IHC). The associations between Wls expression and clinicopathological factors as well as survival time, including overall survival (OS) and disease-free survival (DFS) were analyzed. Bioinformatics analysis was used to reveal the correlation between Wls genes and associated genes or pathways.

Results

Wls was overexpressed in BC cell lines and tissues. The expression level of Wls was significantly correlated with tumor size, estrogen receptor (ER), progesterone receptor (PR), Ki-67, molecular classification, and follow-up status. Spearman correlation analysis showed that Wls protein expression was negatively correlated with ER and PR, which was confirmed by bioinformatics analysis in mRNA level. However, there were positive relationships with MBNG (modified Black's nuclear grade), tumor size, Ki-67, molecular classification, follow-up, and vital status. Univariate and multivariate analysis showed that Wls was an independent prognostic factor for OS and DFS in BC patients. Moreover, Wls was a significant prognostic indicator of OS and DFS in a hormone receptor-positive (HR+) subgroup. GSEA showed that estrogen and androgen response, as well as epithelial-mesenchymal transition pathways, were up-regulated in the Wls high-expression group.

Conclusion

Overexpression of Wls is a significant marker of worse prognosis in BC and might play a crucial role in the HR+ subgroup.

Prevalence of Molecular Subtypes of Breast Cancer in India: a Systematic Review and Meta-analysis

In the last two decades, India has witnessed a substantial increase in the incidence of breast cancer and associated mortality. Studies on the prevalence of molecular subtypes of breast cancer in India have reported inconsistent results. Therefore, we conducted a systematic review of observational studies to document the prevalence of molecular subtypes of breast cancer. A complete literature search for observational studies was conducted in MEDLINE and EMBASE databases using key MeSH terms ((molecular classification) OR (molecular subtypes)) AND (breast cancer)) OR (breast carcinoma)) AND (prevalence)) AND (India). Two reviewers independently reviewed the retrieved studies. The screened studies satisfying the eligibility were included. The quality of included studies was assessed using the selected STROBE criteria. The overall pooled prevalence of luminal A, luminal B, HER2-enriched, and triple-negative breast cancer (TNBC) subtypes of breast cancer were 0.33 (95% CI 0.23-0.44), 0.17 (95% CI 0.12-0.23), 0.15 (95% CI 0.12-0.19), and 0.30 (95% CI 0.27-0.33), respectively. Subgroup analyses were performed by mean age of patients, time period, region, and sample size of the study. Among molecular subtypes of breast cancer, luminal A was the most prevalent subtype followed by TNBC, luminal B, and HER2-enriched subtypes. The overall prevalence of TNBC in India is high compared to other regions of the world. Additional research is warranted to identify the determinants of high TNBC in India. Differentiating TNBC from other molecular subtypes is important to guide therapeutic management of breast cancer.

Androgen receptor expression in a Sri Lankan patient cohort with early breast carcinoma

BACKGROUND

Androgen receptor (AR) expression is emerging as a prognostic biomarker in breast carcinoma (BCa). The study aimed to determine the prevalence of AR expression by immunohistochemical analysis among a cohort of Sri Lankan women with early BCa and to evaluate its association with clinicopathological features including immunohistochemical molecular subtype and early survival.

METHOD

We studied the clinical and pathological features and immunohistochemical profile of 141 women undergoing primary surgery for early BCa, followed by standard adjuvant therapy. AR status was assessed by immunohistochemistry in all cases. Overall survival (OS) and disease-free survival (DFS) was determined. The relationship between AR expression and clinical and pathological parameters and immunohistochemical molecular subtype was analyzed using Student T test and chi-square tests. Cox regression analysis was used to analyze the prognostic impact of AR expression.

RESULTS

AR expression was seen in 40.8%(95%CI 33.10-49.07%) of the BCa study cohort. None of the clinical data studied showed a significant association with the AR status(p > 0.05). Ductal carcinoma in situ(p = 0.003), oestrogen receptor (ER) (p = 0.001) and progesterone receptor (PR) (p = 0.001) positivity and luminal IHC molecular subtype(p = 0.016) were significantly associated with AR-positive status. AR-negative status was significantly associated with tumour necrosis > 50%(p = 0.031), moderate to extensive lymphocytic infiltrate at the tumour margin(p = 0.025) and basal triple negative breast carcinoma(p = 0.016). The mean duration of patient follow-up was 46.70(95% CI 46.495-46.905) months (3.89 years). On univariate analysis, AR-positivity was associated with better OS among ER-positive tumours(p = 0.047), specifically in postmenopausal women (p = 0.030). In ER-negative tumours, AR positivity was associated with worse DFS (p = 0.036). On multivariate analysis, TNM stage and ER/AR status were predictive of survival. ER-positive/AR-positive (ER+/AR+) tumours demonstrated better OS than ER-positive/AR-negative (ER+/AR-) tumours(p = 0.015). ER-negative/AR-positive (ER-/AR+) tumours (p = 0.014) had a worse DFS than ER-negative/AR-negative (ER-/AR-) tumours.

CONCLUSIONS

AR prevalence obtained was low. AR positivity was associated with positivity for ER and PR. On multivariate analysis, apart from TNM stage only ER/AR status were predictive of OS and DFS, with concordant expression of ER/AR demonstrating a better, early survival.

Meta-Analysis of Prevalence of Triple-Negative Breast Cancer and Its Clinical Features at Incidence in Indian Patients With Breast Cancer

PURPOSE

Breast cancer is the most common cancer in women in India, with higher incidence rates of aggressive subtypes, such as triple-negative breast cancer (TNBC).

METHODS

A systematic review was performed to compute pooled prevalence rates of TNBC among patients with breast cancer, and clinical features at presentation were systematically compared with non-TNBC in an Indian cohort of 20,000 patients.

RESULTS

Combined prevalence of TNBC among patients with breast cancer was found to be on the higher side (27%; 95% CI, 24% to 31%). We found that the estrogen receptor (ER) expression cutoff used to determine ER positivity had an influence on the pooled prevalence and ranged from 30% (ER/progesterone receptor [PR] cut ff at 1%) to 24% (ER/PR cutoff at 10%). Odds for TNBC to present in the younger age-group were significantly higher (pooled odds ratio [OR], 1.35; 95% CI, 1.08 to 1.69), with a significantly younger mean age of incidence (weighted mean difference, -2.75; 95% CI, -3.59 to -1.92). TNBC showed a significantly higher odds of presenting with high grade (pooled OR, 2.57; 95% CI, 2.12 to 3.12) and lymph node positivity (pooled OR, 1.39; 95% CI, 1.21 to 1.60) than non-TNBC.

CONCLUSION

Systematic review and meta-analysis of 34 studies revealed a high degree of heterogeneity in prevalence of TNBC within Indian patients with breast cancer, yet pooled prevalence of TNBC is high in India. High proportions of patients with TNBC present with aggressive features, such as high grade and lymph node positivity, compared with patients without TNBC. We emphasize the need for standardized methods for accurate diagnosis in countries like India.

Neoadjuvant Chemotherapy in Triple Negative Breast Cancer: Correlation between Androgen Receptor Expression and Pathological Response

Background:

There is growing evidence that the response to chemotherapy may be affected by Androgen Receptor (AR) expression suggesting that triple-negative breast cancers (TNBC) AR+ and quadruple negative breast cancer (QNBC) subtypes may have different diseases behavior.

Methodology:

We retrospectively estimated the predictive value of the AR expression in stage II and stage III TNBC patients treated with neoadjuvant chemotherapy (NAC) and correlated with the rate of pathological response (pCR).

Results:

Of 89 TNBC patients, 29 patients (32.6%) were TNBC AR+ and 60 patients (67.4) were QNBC. Most of the patients were less than 60 years old. Of note, approximately 62% in the QNBC group were less than 40 years old compared with 39 % in the TNBC AR+ group. The Ki-67 expression was higher in the QNBC in comparison with TNBC AR+ being 86.7% and 65.5%, respectively. QNBC subgroup showed higher rates of pCR compared with TNBC; 60% and 24%, respectively. Higher Ki-67 expression, higher grade, and lymph node involvement were statistically significantly correlated with the rate of pCR in the QNBC group (p=0.02, p=0.04, and p=0.03, respectively). In contrast, no significant association was observed between pCR and clinical-pathological features in the TNBC AR+ group.

Conclusion:

Our results suggested that the AR expression in TNBC may be applied as a predictive marker for NAC. TNBC AR+ had a lower rate of pCR compared with QNBC, suggesting that this subtype may have a partial chemoresistance.

Androgen receptor gene expression in primary breast cancer

We studied androgen receptor (AR) gene expression in primary breast cancer (BC) to determine associations with clinical characteristics and outcomes in the I-SPY 1 study. AR was evaluated in I-SPY 1 (n = 149) using expression microarrays. Associations of AR with clinical and tumor features were determined using the Wilcoxon rank sum test (two-level factors) or the Kruskal-Wallis test (multi-level factors). We identified an optimal AR cut-point to maximize recurrence-free survival (RFS) differences between AR biomarker stratified groups, and assessed the association between the AR stratified groups and RFS using the Cox proportional hazard model. Pearson correlations between AR and selected genes were determined in I-SPY 1, METABRIC (n = 1992), and TCGA (n = 817). AR was lower in triple negative BC vs. hormone receptor positive (HR+)/HER2- and HER2+ disease (p < 0.00001), and lower in basal-like BC (p < 0.00001). AR was higher in grade I/II vs. III tumors (p < 0.00001), in patients >age 50 (p = 0.05), and in node negative disease (p = 0.006). Higher AR was associated with better RFS (p = 0.0007), which remained significant after receptor subtype adjustment (p = 0.01). AR correlated with expression of luminal, HER2, and steroid hormone genes. AR expression was related to clinicopathologic features, intrinsic subtype, and correlated with improved outcome.