For which group of patients with prostate cancer we can expect the highest therapeutic gain due to application of radiotherapy after radical prostatectomy?
Article published in Urologia Polska 2008/61/Supl. 1.

authors

Piotr Milecki, Zbigniew Kwias, Andrzej Antczak, Michał Hrab

Wielkopolskie Centrum Onkologii w Poznaniu
Katedra i Klinika Urologii AM w Poznaniu

summary

Introduction.

Postoperative radiotherapy is regarded as a standard adjuvant treatment for patients after radical surgery in many oncological tumours. However, in prostate cancer postoperative radiotherapy after radical prostatectomy is still matter of debate because of lack of significant evidence that such combined therapy is associated with prolongation of overall survival.

Objectives.

Aim of this study was to evaluate the influence of postoperative radiotherapy (RT) after radical prostatectomy (RP) in groups of patients with prostate cancer defined as low- and high-risk groups of disease progression.

Materials and methods.

Into analysis were included 238 patients with diagnosis of adenocarcinoma of prostate who were treated in our centre between 1999 and 2004. For all patients in whom open retropubic RP was performed the following parameters were described: Gleason score, postoperative pathological margin, performance status according to ECOG scale (0-1), and PSA <0.2 ng/ml in two consecutive measurements. All patients after RP were divided into two groups (RP + RT and RP without RT) and in addition patients were divided into low- and high-risk subgroups of disease relapse. Low-risk group (+ margin, PSA <10 ng/ml, Gleason score <8) was defined in 33 patients (RP) versus 39 patients (RP + RT). High-risk group (pT3b, PSA >10 ng/ml, Gleason score >7) was defined in 71 patients (RP) versus 95 patients (RP + RT). RT was applied no later than 6 months after surgery for patients with the following risk factors of relapse as positive postoperative margin, pT3a, pT3b. All patients were

subjected to open retropubic radical prostatectomy. RT was based on three-dimensional conformal treatment planning. Mean total dose applied to irradiated patients was 60,4 Gy (range: 56 Gy - 64 Gy).

Results.

Our results have not indicated significant differences in cause specific survival, overall survival, and distant metastases free survival for groups of patients treated with RT or without Rt after RP. In low-risk group of patients biochemical progression free survival was as follow; 95% (RP + RT) versus 70% (RP), p=0,037. In high-risk group of patients biochemical progression free survival was 71% (RP + RT) versus 63% (RP), p=0,072.

Conclusions.

In low-risk group of disease progression (+margin, pT3a, Gleason score< 8, PSA <10 ng/ml) patients after RP adjuvant RT was associated with prolongation of time without biochemical relapse, but without significant impact on survival. Thus, application of RT after RP should be in each case discussed with patient. In group of patients with high-risk of disease progression (pT3b, Gleason score >7, PSA >10 ng/ml) postoperative RT was not related with prolongation of time without biochemical progression.