[Prostate cancer: has local radiation treatment had an impact on survival?]

Local control is an important goal in the treatment of prostate cancer. Firstly, it avoids the morbidity due to locoregional evolution (urethral obstruction, vascular compression, rectal or vesical involvement). Moreover, local control of the disease may decrease the mortality due to metastases disseminated from local relapse. Local control evaluation remains difficult: neither rectal examination nor imaging or prostate biopsies have an absolute value in diagnostic of local relapse. PSA increase does not permit to differentiate local from distant relapses. Recent developments in radiotherapy techniques allow dose escalation without major toxicity. Retrospective studies and one randomized study have shown that an increase from 70 to 80 Gy or more, improve biological relapse-free survival. In one randomized study comparing 70 to 78 Gy, the biochemical disease-free survival was improved from 69 to 79% at five years. Such an improvement can only be explained by an improvement of local control. The benefit in term of overall survival is not yet demonstrated and needs a longer follow-up and other studies. Another approach to improve local control is the association of a local radiotherapy with hormonal adjuvant therapy. Four randomized studies have been published for locally advanced prostate cancer. These studies have all demonstrated an improvement of local control, and a decrease of metastatic risk. The benefit in term of overall survival, observed in one of this trial, may be explained by the improvement of either local or distant control or both. Such therapeutic progress, associated with the development of prostate cancer screening should lead to a decrease of prostate cancer mortality for the next ten years.