The value of radiotherapy in treating recurrent prostate cancer after radical prostatectomy

Approximately 25–40% of men who undergo radical retropubic prostatectomy (RRP) for the treatment of clinically localized prostate cancer will experience biochemical recurrence. A rapid prostate-specific antigen (PSA) doubling time or high-grade disease are risk factors for progression to bone metastases and cancer-specific mortality. Salvage external-beam radiotherapy (EBRT) to the prostate fossa is the only curative therapy for patients with biochemical recurrence after RRP, but it is used relatively infrequently to treat recurrent prostate cancer because of a widespread perception that most patients have systemic recurrence, and its reported lack of efficacy for high-risk disease. However, in a large, multicenter study of patients who received salvage EBRT for a rising PSA level after RRP, a substantial proportion of patients with high-grade disease and/or a rapid PSA doubling time were observed to have a favorable outcome after salvage EBRT if it was administered at low PSA values. This suggests that salvage EBRT could provide long-term cancer control for patients at the highest risk of progression to bone metastases and cancer-specific mortality. A nomogram that predicts the 3-year progression-free probability after salvage EBRT has been developed to facilitate the selection of patients for this potentially curative therapy. In the absence of other curative therapies, all patients with recurrent prostate cancer should be considered for salvage EBRT, particularly those with positive surgical margins. To be successful, salvage EBRT should be administered at the earliest evidence of recurrent disease, once a rising PSA trend as been confirmed.