PTGS2 and prostate cancer: Interestingly, COX-2 overexpression was associated with worse PSA failure (by ASTRO definition) for those on the control arm of RT + STAD but not those on the RT + LTAD (p = 0.002), suggesting that COX-2 may serve as a predictive biomarker for length of ADT therapy in high-risk and locally advanced prostate cancer patients.