Androgen receptor expression in breast cancer among Chinese patients

Abstract

Background: Breast cancer is a significant disease, and its heterogeneity is reflected by receptor expression. Androgen receptor (AR) is frequently expressed in breast cancer but it is not used as a prognostic marker. AR is encoded by a 90kb long gene, is involved in hormonal signaling and is known for interaction with the estrogen receptor (ER). In the past decade AR’s dual role in breast cancer has been investigated and findings show it may serve as an effective prognostic marker in breast cancer. Materials and methods: Using immunohistochemistry, 141 cases were analyzed using tissue microarray (TMA). AR expression pattern is scored and correlated with age of first diagnosis, lymph node status, tumor size/stage/grade/type, ER/PR/HER2 status, disease relapse and metastasis. Results: AR expression is correlated positively with ER positivity, and negatively with tumor size and triple negativity (ER-/PR-/HER2-) with p-values of 0.001, 0.007 and 0.001 respectively. There is a trend of increased survival measured using Kaplan-Meier log-rank analysis with p-value of 0.004 for overall survival and 0.036 for disease-specific survival; cox regression survival also shows correlation with AR expression with a p-value of 0.005 for overall survival and 0.04 for disease specific in univariate analysis. Conclusion: AR expression is significantly correlated with tumor size, ER positivity and triple negativity (ER-/PR-/HER2-) in a Chinese cohort. AR expression is also associated with increased patient survival and may serve as a prognostic marker in breast cancer.