Abstract 3822: Expression of androgen receptor and CD24 correlates with improved 5-year survival in Pakistani patients with invasive breast cancer

Abstract

Abstract Introduction: Androgen receptor (AR) expression has been shown to correlate with improved survival in luminal A, B and triple negative (TN) breast cancer (BCa). Cancer stem cells (CSC) with CD44+/CD24- and ALDH1+ phenotype is associated with pro-invasive gene signature in BCa. Aim of our study was to evaluate prognostic significance of AR expression in relation to CD44, CD24 and ALDH1 in invasive BCa. Methodology: Immunohistochemical expression of AR, CD44, CD24 and ALDH1 was evaluated in 180 FFPE blocks of BCa cases from one institution. Clinico-pathological details and follow-up data were collected from medical charts. Data was analyzed on SPSS 19. Five-year survival was estimated by Kaplan Meier. Results: Median age of patients was 55 years (range: 28-87). Fifteen percent of patients were diagnosed with stage I, 52.2% with stage II, 25% with stage III and 7.8% with stage IV disease. Mean duration of follow-up was 4.5 years (SD+ 2.7) and 29% mortalities were attributed to BCa. AR was expressed in 63.9%, ER in 61%, PR in 51% & HER-2/neu in 30% of tumors. CD44, CD24 and ALDH1 were expressed in 60%, 43.3% & 28.3% of tumors respectively. AR expression was associated (p-value<0.001) with grade II tumors expressing ER, PR and CD24 but lacking ALDH1. Multivariable analysis confirmed AR (adjusted HR 0.43, 95% CI 0.19-0.95) and PR (adjusted HR: 0.20, 95% CI: 0.07-0.60) to be independently associated with better outcome. Five year survival of patients with AR+ versus AR- expressing tumors, showed that patients with AR+ tumors had significantly better outcome (p-value=0.03) with survival advantage of 39.6 months. Survival advantage decreased by 9.6 months in tumors expressing CD44+/CD24-/AR- (p-value=0.01) phenotype and by 12 months in patients whose tumors were phenotypically ALDHI+ /AR- (p-value=0.12). We stratified TN tumors into 2 groups: A. TN/CD24+/AR+; B. TN/CD24-/AR- and found that group A tumors had a trend towards better 5 survival (p-value=0.09). Conclusions: Three individual markers (CD44, CD24, AR) may afford prognostic information. Combinations of CD44, CD24 and AR permitted patient stratification into 3 risk categories: poor risk CD24-/AR-; intermediate risk CD44+/CD24-/AR- and good risk CD24+/AR+. Stratification of TN group showed that loss of AR and CD24 was associated with poorest outcome. These results underscore the relevance and importance of AR and CD24 as prognostic markers in invasive BCa. Citation Format: Nazia Riaz, Romana Idress, Sadia Habib, Azhar Hussain, El-Nasir Lalani. Expression of androgen receptor and CD24 correlates with improved 5-year survival in Pakistani patients with invasive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3822. doi:10.1158/1538-7445.AM2017-3822