Value of positive resection margins in patients with pT2 prostate cancer. Implications for adjuvant treatment

Abstract

ObjectiveTo analyze the impact on the recurrence-free biochemical survival of tumor involvement of surgical resection margins in patients with localized prostate cancer (pT2) in the prostatectomy specimen and its implications for adjuvant treatment. Materials and methodRetrospective study of 536 patients with stage pT2 prostate cancer, treated with radical prostatectomy between 1996 and 2007. Subsequent to the prostatectomy, the following variables were collected: Gleason score, pathological stage, capsular invasion, surgical margins and perineural invasion. We performed a univariate analysis and subsequently adjusted it by means of a Cox proportional hazard model (enter method). Results21.7% presented positive surgical margins and 20.9% developed biochemical recurrence after a mean follow-up of 57 months. 37.9% of the patients with pathological involvement of the resection surgical margins presented biochemical recurrence against 16% that did not have it (p<0.001). In the multivariate analysis, only the surgical margin (p<0.001) and the Gleason score greater or equal to 8 (p<0.001) behaved as independent biochemical recurrence factors. On stratifying the series according to these two variables, we found that the patients with positive surgical margins and a Gleason score of ≤7 have a recurrence probability at 5 and 10 years of 35% and 50% against 74% and 87% in the group with positive surgical margins and a Gleason score of ≥8 (p=0.002). ConclusionPatients with pT2 prostate cancer, positive surgical margins and a Gleason score of ≥8 will benefit from adjuvant radiotherapy. 50% of the patients with positive margins and a Gleason score of ≤7 will not recur, which means that the indication of adjuvant radiotherapy continues to be controversial.