Krebswissenschaft und -therapie

Using of Androgen Receptor Expression as a Novel Potential Biomarker in Predicting Survival of Women with Metastatic Triple Negative Breast Cancer

Abstract

Mirco Pistelli, Alessandra Pagliacci, Zelmira Ballatore, Mariagrazia De Lisa, Tommasina Biscotti, Alfredo Santinelli, Nicola Battelli, Miriam Caramanti, Francesca Ridolfi, Elena Maccaroni, Raffaella Bracci, Rossana Berardi and Stefano Cascinu

Background and objective: The androgen receptor (AR) is a member of the steroid receptor subfamily with well-known biological and therapeutic importance in prostate cancer. There is evidence that the androgen signalling pathway may play a critical role also in normal and malignant breast tissue. They are highly expressed in triple negative breast cancer (TNBC) but it is not clear if AR expression is correlated with survival in advanced TNBC. Therefore, in the present study we investigated the prognostic value of AR expression in metastatic TNBC.

Patients and methods: Stage IV TNBC was included in the analysis. Patients with poor performance status (ECOG>2) were excluded. Tumors with >10% nuclear-stained cells were considered to be positive for AR. Univariate and multivariate analyses were performed.

Results: From a database of 208 TNBC patients, 24 cases of advanced TNBC were identified; out of 24 patients, 33% were AR positive. The median age at diagnosis was 61 years (range 30-78 years). All patients included in the study received first-line chemotherapy for their disease. Median progression free-survival (mPFS) and overall survival (OS) were 3.5 months (range 0.3-27.3 months) and 25.9 months (range 2.52-122.2 months), respectively. Univariate analysis showed that AR negative advanced TNBC had a significantly worse PFS (3.2 vs 7.9 months; p=0.02; HR=2.57, 95% CI 1.15-10.53) and OS (20.5 vs 47.4 months; p=0.01; HR=2.88, 95% CI 1.32- 9.43). Multivariate analysis confirms that AR expression was an independent prognostic factor of PFS (p=0.04; HR=2.19, 95% CI 1.52-5.91), as well as for OS (p=0.05; HR=2.21, 95% CI 0.98-2.55).

Conclusions: Our preliminary results suggested that the assessment of AR expression may be a useful tool to identify patients with a good or a poor prognosis. Furthermore, since that about one third of metastatic TNBC expressed ARs, they may represent a target for novel potential treatment options in advanced TNBC.