Hobbs, Corey J

Objective To update a previously proposed prognostic scoring system that predicts risk of biochemical recurrence ( BCR ) after salvage radiation therapy ( SRT ) for recurrent prostate cancer when using additional patients and a PSA value of 0.2 ng/ mL and rising as the definition of BCR . Patients and Methods We included 577 patients who received SRT for a rising PSA after radical prostatectomy in this retrospective cohort study. Clinical, pathological, and SRT characteristics were evaluated for association with BCR using relative risks ( RR s) from multivariable Cox regression models. Results With a median follow‐up of 5.5 years after SRT , 354 patients (61%) experienced BCR . At 5 years after SRT , 40% of patients were free of BCR . Independent associations with BCR were identified for the PSA level before SRT ( RR [doubling]: 1.25, P < 0.001), pathological tumour stage ( RR [T3a vs T2] 1.21, P = 0.19; RR [T3b/T4 vs T2] 2.09, P < 0.001; overall P < 0.001), Gleason score ( RR [7 vs <7] 1.63, P < 0.001; RR [8–10 vs <7] 2.28, P < 0.001; overall P < 0.001), and surgical margin status ( RR [positive vs negative] 0.71, P = 0.003). We combined these four variables to create a prognostic scoring system that predicted BCR risk with a c ‐index of 0.66. Scores ranged from 0 to 7, and 5‐year freedom from BCR for different levels of the score was as follows: Score = 0–1: 66%, Score = 2: 46%, Score = 3: 28%, Score = 4: 19%, and Score = 5–7: 15%. Conclusion We developed a scoring system that provides an estimation of the risk of BCR after SRT . These findings will be useful for patients and physicians in decision making for radiation therapy in the salvage setting.