Androgen receptor expression in triple negative breast cancer: A report from a tertiary care center.

Abstract

Context: The role of androgen receptor (AR) as a prognostic marker in triple negative breast cancer (TNBC) has been ambiguous since existing reports illustrate conflicting results.

Aims: To compare clinicopathological features and survival between AR-positive TNBC and QNBC.

Methods and material: A total of 281 subjects were included and tissue microarrays (TMA) were constructed using tumor tissue cores from their formalin-fixed paraffin-embedded blocks. The testing of AR expression was done using immunohistochemistry on TMA slides. Tumors with at least 1% nuclear staining were considered to be positive for AR expression. Comprehensive data were gathered from electronic medical records and analyzed using statistical tests.

Results: The expression of AR was positive in 52 cases. The TNBC subgroup with a positive family history of cancer had a significantly higher frequency (P = 0.011) of second primary occurrence. AR expression was significantly associated with higher age at diagnosis (P = 0.006), smaller tumor size (P = 0.033), lower tumor grade (P < 0.001), non-basal-like phenotype (P < 0.001), and distant recurrence (P = 0.024). At a median follow-up period of 88 (range 0-137) months, a 10-year disease-free rate was higher in quadruple negative breast cancer (QNBC) (78% vs. 73%) compared to AR-positive TNBC. Likewise, the 10-year overall survival rate in QNBC was superior (75% vs. 72%) to AR-positive TNBC.

Conclusions: AR is expressed in one-fifth of all TNBC. AR expression is associated with smaller tumor size, lower tumor grade, higher age, and distant recurrence. AR-positive TNBC exhibits shorter disease-free survival and overall survival than QNBC.