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

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.

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

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.

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.

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.