Radiotherapy after radical prostatectomy: immediate or early delayed?

BACKGROUND: Biochemical recurrence after radical prostatectomy (RP) is associated with risk indicators, including Gleason score, preoperative PSA level, tumor stage, seminal vesicle invasion, and positive surgical margins. The 5-year biochemical progression rate among predisposed patients is as high as 50-70%. Post-RP treatment options include adjuvant radiotherapy (ART, for men with undetectable PSA) or salvage radiotherapy (SRT, for PSA persisting or re-rising above detection threshold). Presently, there are no published randomized trials evaluating ART vs. SRT directly.
METHODS: Published data on ART and SRT were reviewed to allow a comparison of the two treatment approaches.
RESULTS: Three randomized phase III trials demonstrated an almost 20% absolute benefit for biochemical progression-free survival after ART (60-64 Gy) compared to a "wait and see" policy. The greatest benefit was achieved in patients with positive margins and pT3 tumors. SRT can be offered to patients with elevated PSA after RP. In 30-70% of SRT patients, PSA will decrease to an undetectable level, thus giving a second curative chance. The rate of side effects for both treatments is comparably low. The role of irradiation of pelvic lymph nodes and the additional use of hormone therapy and radiation dose are discussed.
CONCLUSION: It remains unclear whether early SRT initiated after PSA failure is equivalent to ART. Where SRT is indicated, it should be started as early as possible.