PO116 DISCORDANCE IN TRIPLE-RECEPTOR STATUS BETWEEN PRIMARY AND RECURRENT BREAST CANCER

Abstract

s / The Breast 22 S3 (2013) S19–S63 S59 attention in recent years, especially due to its expression in ER and PR negative breast carcinomas. This current study aims to investigate the expression patterns of AR in a large cohort of Indian BC patients, with a focus on clinicopathological parameters, steroid receptors, and breast cancer of different molecular subtypes and response to taxane and/or anthracycline based standard chemotherapy regimen. Materials and Methods: Between May 2011 and Sept 2012, 116 breast cancer patients were enrolled. Tissue sections were immunostained for ER, PR, Her2 Neu and AR. 80 cases (69.7%) presented with LABC; n=72 patients were subjected to NACT taxane and/or anthracycline based according to standard treatment guidelines. Clinical response was evaluated using revised RECIST guidelines (version 1.1). Results: In particular, AR expression was commonly observed in luminal A 21/27 (77.8%) and B 19/30 (63.3%) BC but was less frequently seen in HER2 cancers 16/29 (55.1%). Despite being defined by the absence of ER and PR expression and being considered hormonally unresponsive, 9/30 (30%) of TNBC expressed androgen receptor. 72.2% of ER positive BC patients also expressed AR (p=0.001) with 73.9% of PR positive BC patients also expressing AR (p=0.001). AR expression was more in low T stages of the disease (65.4% in T2 stage compared to 47.1% in T4 stage) (p=0.059). AR expression was higher in low nodal stage (72.7% in N0 stage as compared to 33.3% in N2 stage) (p=0.042). In patients offered NAC (n=72), response grading was done with majority of patients showing partial response (PR) (65.3%) and 12/72 (16.7%) patients having complete response (CR). Seven patients with progressive disease (PD) and 6 with stable disease (SD) who were non-responders, were offered different chemotherapy regimens. AR expression was higher in responders (55.3% in PR group and 50.0% in CR group) as compared to non-responders (16.7% in SD group and 28.7% in PD group). Conclusion: The present study was performed to evaluate the expression of AR in BC, and its correlation with the clinicopathological parameters, established biomarkers like ER/PR. AR expression was found to be significantly associated with lower T-stage of cancer and high percentage of responders to NACT in LABC. As AR is confirmed as biologically relevant, it is possible that hormonal manipulations targeting it could be useful in treatment but large sample size is needed to deduce the final statement.