(UroToday.com) Overall survival (OS) is widely accepted as the most relevant outcome for the assessment of cancer-directed treatments. However, in prostate cancer, the natural history may be protracted and, as such, there has been considerable interest in identifying surrogate outcomes which may be more rapidly assessed. Radiographic progression-free survival (rPFS) is one such potential surrogate outcome that is commonly used as a co-primary endpoint in randomized clinical trials in men with metastatic castrate-resistant prostate cancer (mCRPC). In the Prostate, Testicular, Penile Poster session at the 2021 American Society of Clinical Oncology Annual Meeting, Dr. Susan Halabi presented an analysis assessing whether rPFS is a reliable surrogate for OS in mCRPC.