ASCO GU 2017: Clinical significance of AR mRNA quantification from circulating tumor cells in men with metastatic castrate resistant prostate cancer treated with abiraterone or enzalutamide - Session Highlights
No data is available on the effect of full length AR mRNA (AR-FL) quantification on prostate cancer outcome. In order to examine this effect a trial was designed in order to quantify AR-FL mRNA in CTC's and correlate it with treatment outcomes. The AR-FL mRNA was quantified by qPCR for complementary DNA specific for AR_FL. 202 patients were enrolled prior to abi/enza treatment. The patients were stratified into 3 groups according to the amount of AR-FL mRNA found in their CTC's: negative (no CTC's or no AR-FL mRNA), low (mRNA<median) and="" high="" (mrna="">median). There was strong correlation between AR-FL and AR-v7. Also, an inverse relation was found between AR-FL and 50% decline in PSA. Negative, low and high AR-FL patients had PSA decline in 62%, 54% and 28% respectively. AR-FL status was correlated with PSA and radiographic progression free survival and overall survival. On MVA, AR-FL was significant for predicting PSA PFS and OS. AR-V7 remained independently prognostic for all outcomes in MVA. This trial suggests that AR-FL copy number is prognostic for clinical outcome in abi/enza treated patients. Furthermore, AR-FL quantification could serve as another molecular marker in addition to AR-V7 splice variant.
Presenter: Emmanuel Anatonarakis, MD
Written By: Miki Haifler, MD, M.Sc, Fox Chase Cancer Center
at the 2017 Genitourinary Cancers Symposium - February 16 - 18, 2017 – Orlando, Florida USA