882P Activating mutations in AKT1/PIK3CA are associated with poor clinical outcomes in metastatic prostate cancer (mPC)

Background Hotspot activating mutations in AKT1 and PIK3CA occur uncommonly in mPC. The incidence and clinical course of patients (pts) with AKT1/PIK3CA hotspot mutations (A/P HSM) is poorly characterised. Methods We performed deep targeted sequencing on 1381 cell-free DNA samples from 773 pts with mPC. We evaluated PSA decline ≥50% from baseline (PSA50), time from androgen deprivation therapy (ADT) to castration-resistant prostate cancer …