Association between androgen receptor status and prognosis in triple negative breast cancer

Triple negative breast cancer (TNBC) is a heterogeneous disease group with a higher recurrence risk and poorer prognosis. In this study, we aimed to investigate the frequency and prognostic value of androgen receptor (AR) expression in tissues of TNBC patients.

A total of 84 TNBC patients treated between 2000 - 2015 in Hacettepe University Cancer Institute were included and their medical records were analyzed retrospectively. The available paraffin blocks were assessed immunohistochemically to determine AR expression. Tumors with ≥1% nuclear staining were considered AR-positive, while the ones with <1% staining were considered AR-negative. We analyzed the association between AR expression, and clinical-pathologic characteristics and prognosis in TNBC.

Of the 84 TNBC patients, 25 (29.8%) were AR-positive. The frequency of grade 3 tumors was lower among AR-positive TNBC tumors compared to AR-negative tumors (40 vs 86.4%, p<0.001). In the AR-positive group, invasive ductal carcinoma (IDC) was less prevalent compared to AR-negative group (56 vs 86.4%, p<0.002). However, there were not statistically significant differences between AR positive and negative groups in terms of overall survival (OS) and disease free survival (DFS) (p=0.449, p=0.733, respectively). We found that grade 3 tumors were less frequent in AR-positive TNBC in our study. Nonetheless, we did not detect statistically significant difference in terms of overall survival and disease free survival between AR positive and negative TNBC.

Routine evaluation of AR could contribute to further studies that may enlighten the role of AR targeting therapies in TNBC.