Prognostic relevance of androgen receptor detection in operable breast cancer

Abstract

Background and objectives: Androgen receptor (AR) is relevant for prognostication in breast cancer. Different determination methods and cut-off levels hamper interpretation and comparisons of studies. Long-term prognostic evaluation of different AR assays in patients comprising operable breast cancers is scarce.

Methods: AR was evaluated in 120 primary tumors using the dextran-coated charcoal method (charc-AR), and quantitative immunohistochemistry (IHC) on whole sections (WS) and tissue microarrays (TMA). Nuclear and cytoplasmic-AR localization was determined, and the prognostic importance of AR assays was assessed. Comparisons and correlations with the mitotic activity index (MAI), estrogen receptor (ERalpha), progesterone receptor (PR), HER-2, and histological grade (WHO I-III) were made.

Results: Nuclear-AR in WS, but not charc-AR, strongly correlated with MAI (P = 0.001). However, prognostic information appeared in univariate survival analyses only. Nuclear-AR in TMA was not prognostic. Charc-AR was independent prognostic in node positives both for relapse free survival (RFS) and breast cancer specific survival (BCSS). Both charc-AR and IHC cytoplasmic-AR provided independent prognostic survival information for BCSS in women <55 years.

Conclusion: Methods that can detect AR localized in the cytoplasm yield important prognostic information, and further studies in patients with operable breast cancer are warranted.