Expression of Androgen Receptor in Inflammatory Breast Cancer and Its Clinical Relevance

BACKGROUND: Inflammatory breast cancer (IBC) is characterized by an aggressive clinical course with early metastasis and frequent resistance to conventional therapies. Identifying a novel therapeutic approach may improve the prognosis for patients with IBC. Because androgen receptor (AR)-expressing tumors may be targeted by anti-AR therapy, the authors examined the prevalence of AR expression in IBC tumors and explored its clinical relevance. METHODS: Tissue microarrays of 88 IBC tumors were stained immunohistochemically with monoclonal antibody against AR, and the results were correlated with clinicopathologic parameters and survival outcomes. RESULTS: The median follow-up was 10.8 years. AR was positive in 39% of the IBC tumors and in approximately one-third of estrogen receptor (ER)-negative and progesterone receptor (PR)-negative tumors. AR positivity was significantly associated with lymphovascular invasion (P = .01) but not with other clinicopathologic parameters. There was a trend toward an association between AR expression and PR expression (P = .07). In univariate survival analysis, patients who had AR-negative/ER-negative tumors had significantly worse overall survival (P = .03) and disease-specific survival (P = .04) than patients who had tumors with other combinations of AR/ER status. CONCLUSIONS: AR expression was common in IBC tumors, and AR positivity was significantly associated with lymphovascular invasion. Patients who had AR-negative/ER-negative tumors had the worst survival outcomes. Further study with a larger series will be required to delineate the biologic mechanisms of AR and their clinical significance in IBC tumors. (C) 2014 American Cancer Society.