Androgen receptor expression in triple negative breast cancer patients and its predictive value for clinical outcomes

Abstract

Objective To investigate androgen receptor(AR) expression in triple negative breast cancer(TNBC) patients and its predictive value for clinical outcomes. Methods Five hundred and sixty-eight primary breast cancer patients who received surgery treatment from January 2008 to January 2010 were included in this study.Tissue sections of surgical resection specimens were underwent estrogen receptor(ER), progesterone receptor(PR), and human epidermal growth factor receptor 2(HER2) immunohisto chemical staining, according to the judgment for triple negative breast cancer and non triple negative breast cancer.Data on age, family history, menstruation, tumor size, tumor stage, tumor grade, pathological type and lymph node metastasis were collected for analysis.Immunohistochemical analysis of AR was done in tissue sections of triple negative breast cancer patients, Kaplan-Meier method was used to compare survival between AR(+ ) and AR(-) groups, and Log-rank method was used to determine the association between AR- positive expression and 5-year overall survival as well as disease free survival. Results Among 568 breast cancer patients, 174(30.6%) TNBC patients were identified, including 84 patiens with AR(-) expression and 90 patients with AR(+ ) expression.During 5 years' follow-up, reccurrence rate was 35.7%(30/84) in AR(-) group and 20.0%(18/90) in AR(+ ) group; 5-year overall survival rate was 73.8% in AR(-) group and 81.1% in AR(+ ) group.There was no significant association between AR(+ ) expression and 5-year death or recurrence rate, while after adjusting for age, menstruation, tumor size and lymph node metastasis, AR(+ ) expression was significantly associated with decreased 5-year death and recurrence rate, adjusted hazard ratio(HR) was 0.794, 95CI(0.430-1.021) and 0.722, 95CI(0.451-0.965) respectively. Conclusion AR(-) expression is associated with increased risk of death and recurrence and is a promising predictive marker for poor clinical outcomes. Key words: Triple negative breast cancer; Androgen receptor; Estrogen receptor; Progesterone receptor; Human epidermal growth factor receptor 2; Survival rate