Introduction

Positive surgical margins (PSM) after RP are a known factor associated with BCR. Radiation therapy (RT) currently represents an established option for metastasis-free patients. However, the timing of administration is not univocal._x000D_ The aim of this study is to identify factors related to the indication to adjuvant radiation therapy (aRT) vs salvage (sRT), taking a picture of the contemporary management and prognosis of patients with PSM after radical prostatectomy (RP) at an academic tertiary institution.

Methods

We retrospectively reviewed our perspectively-maintained database. RP has been performed with an open retropubic approach until 2010, then with a robotic transperitoneal one._x000D_ All the cases with PSM and adverse pathological features (stage ≥pT3, GS ≥8) were submitted to a multidisciplinary discussion. The indication to sRT was given if biochemical recurrence (BCR, PSA 0.2 ng/ml), preferably before PSA >0.5 ng/ml._x000D_ Logistic regression models were used to determine the factors associated with RT indication and BCR in univariate and multivariate analysis. The BCR-free survival was calculated using Kaplan-Meier method.

Results

Out of 789 patients, 197 had PSM (overall prevalence 25,2%), with monofocal involvement in 121 (60.8%) and multifocal in 78 (39.2%). _x000D_ An aRT was indicated in 40 patients (20.3%). Findings are summarized in table 1. Factors independently related to aRT indication were: pathological stage, number of sites of PSM and post-operative PSA. The median follow-up time was 51.1 months (IQR 30.9-69.3). Among the 157 patients for whom aRT was not indicated, 39 experienced a relapse of PSA (prevalence of BCR 24.8%, p not significant). 26 were then treated by sRT, 8 by androgen deprivation therapy, 5 underwent surveillance. Overall, a BCR was found in 46 patients (23.4%) after a median time of 24.0 months (IQR 18.0-36.0)._x000D_ At the last available control 176 patients (89.3%) had a PSA < 0.2 ng/ml (median value 0.02). Only pathological stage was significantly related to the risk of BCR.

Conclusions

In a real-life scenario, the indication to aRT is more restrictive than what recommended by guidelines and is driven by the amount of PSM and a detectable post-operative PSA. No differences in BCR free survival are evident in patients with PSM submitted to aRT vs sRT.

Funding

none