Adjuvant and salvage irradiation following radical prostatectomy for prostate cancer

Abstract

We performed a retrospective analysis to assess the durability of benefit derived from irradiation after prostatectomy for pT3N0 disease, and the possibility of cure. We studied 88 patients who were irradiated after prostatectomy and had available prostate specific antigen (PSA) data, no known nodal or metastatic disease, no hormonal treatment, and follow-up of at least 12 months from surgery. Forty patients received adjuvant therapy for a high risk of local failure with undetectable PSA. Forty-eight patients received salvage therapy for elevated PSA levels. Mean follow up was 44 months from date of surgery and 31 months from irradiation. Biochemical failure was strictly defined as a confirmed rise in PSA of >10%, or as the ability to detect a previously undetectable PSA value. After salvage irradiation, 69% of patients attained an undetectable PSA. Eighty-eight percent of adjuvant patients were biochemically and clinically free of disease (bNED) at 3 years from prostatectomy. Sixty-eight percent of those receiving salvage irradiation were bNED 3 years after surgery. On univariate analysis, treatment group (adjuvant or salvage), pre-operative PSA, and the status of seminal vesicles were significant prognostic factors. The extent of PSA elevation in the salvage group was also significant. We did not demonstrate a significant difference between those salvage patients referred for persistently elevated PSA as compared to those with a late rise in PSA. On multivariate analysis, the only significant predictor of outcome was treatment group, with adjuvant irradiation having better outcome than salvage. More than two-thirds of this group of patients remain biochemically disease free at 3 years following irradiation, attesting to a number of potential cures. For patients with stage pT3N0 prostate cancer following radical prostatectomy, our data support the use of either routine postoperative adjuvant irradiation or close PSA follow-up with early salvage treatment.