Postoperative radiotherapy in prostate cancer: Analysis of prognostic factors in a series of 282 patients

Abstract

Aim

To assess the outcomes of patients treated with postoperative RT in relation to the possible prognostic factors.

Background

Postoperative radiotherapy (RT) has been proved to reduce the risk of biochemical recurrence in high-risk prostate cancer patients. Baseline prostate specific antigen (PSA), pathological Gleason score (GS), positive surgical margins, nodal status and seminal vesicle invasion are independent predictors of biochemical relapse.

Materials and methods

The clinical records of 282 patients who underwent postoperative RT were retrospectively reviewed. The prognostic value of postoperative PSA, preoperative risk class, nodal status, pathological GS, margins status, and administration of hormonal therapy (HT) was analyzed.

Results

Postoperative RT was delivered with a median dose to the prostatic fossa of 66[[ce:hsp sp="0.25"/]]Gy (range 50–72) in 1.8–2[[ce:hsp sp="0.25"/]]Gy/fraction. Median follow-up was 23.1 months (range 6–119). Five-year actuarial biochemical disease-free survival (bDFS) and overall survival rates were 76% and 95%, respectively. Higher bDFS was found for patients with postoperative PSA <0.02[[ce:hsp sp="0.25"/]]ng/ml (p[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]0.03), low preoperative risk class (p[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]0.01), pN0 (p[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]0.003), GS 4–6 (p[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]0.0006), no androgen deprivation therapy (p[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]0.02), and irrespective of surgical margin status (p[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]0.10). Multivariate analysis showed that postoperative PSA and Gleason score had a significant impact on bDFS (p[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]0.039 and p[[ce:hsp sp="0.25"/]]=[[ce:hsp sp="0.25"/]]0.05, respectively).

Conclusions

Postoperative RT with a dose of 66[[ce:hsp sp="0.25"/]]Gy offers an acceptable toxicity and an optimal disease control after radical prostatectomy in patients with different risk features. A postoperative PSA >0.02[[ce:hsp sp="0.25"/]]ng/ml could be considered as a prognostic factor and a tool to select patients at risk for progression.