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

Abstract

Background: Breast cancer (BC) is associated with advanced presentation in developing countries like India due to various socio-economic factors. The presence of BC molecular subtypes such as the triple-negative (TN) subtype adds to this menace. Androgen receptor (AR) is emerging as a new biological marker. The aim of this study was to examine the prevalence of AR with relation to different BC subtypes, and its role in predicting response to neoadjuvant chemotherapy. Methods: 116 cases of invasive BC (infiltrating ductal carcinoma, not otherwise specified) were evaluated. AR expression was correlated with clinicopathological factors, established prognostic markers, BC subtypes and it ability for predicting response to neoadjuvant chemotherapy. Results: AR was expressed in 56% of the cases. AR expression was significantly associated with early stage (p < 0.03), low axillary burden (p < 0.04), estrogen receptor (p = 0.002), progesterone receptor (p = 0.001) expression and luminal A molecular subtype. No significant association was observed with age, tumor size and HER2/neu status. One-third of TNBC cases expressed AR. Higher AR expression corelated to good clinical response to neoadjuvant chemotherapy. Conclusion: AR can be utilized as a predictor of response to neoadjuvant chemotherapy especially in developing countries such as India where the load of advanced disease is high.