Radiation therapy for prostate cancer after prostatectomy: adjuvant or salvage?

Approximately 15-25% of men who undergo radical prostatectomy for localized prostate cancer will experience a PSA-defined biochemical recurrence (BCR) of their cancer--men with poorly differentiated cancer, non-organ-confined disease, and positive surgical margins are at the highest risk. Accumulating evidence indicates that postoperative radiation therapy to the prostate bed favorably influences the course of disease in men with pathological features of poor prognosis. Three phase III randomized trials of adjuvant radiotherapy versus observation have reported improved freedom from BCR, and one study has reported improved metastasis-free survival and overall survival. Similar evidence from randomized trials for salvage radiotherapy is lacking; however, several observational studies have reported durable responses to salvage radiotherapy and reduced cancer-specific mortality in a substantial proportion of high-risk patients, provided that it is administered at the earliest evidence of BCR. The appeal of salvage radiotherapy is that a substantial proportion of patients with non-organ-confined cancer or positive surgical margins are cured after radical prostatectomy alone, thereby limiting the adverse effects of postoperative radiotherapy--which include urinary and bowel dysfunction, sexual dysfunction and secondary pelvic malignancies--to only those whose cancer was not cured by surgery. In the absence of data from randomized trials demonstrating the superiority of adjuvant radiotherapy over a surveillance strategy (with planned salvage radiotherapy at the earliest evidence of BCR), we advocate shared decision making between physicians and patients, based on the relative advantages and disadvantages of each approach.