Combination of Androgen Deprivation Therapy and Salvage Radiotherapy versus Salvage Radiotherapy Alone for Recurrent Prostate Cancer after Radical Prostatectomy

Abstract

Introduction: To assess the value of androgen deprivation therapy (ADT) on salvage radiotherapy (RT) in post-prostatectomy recurrent prostate cancer patients, we compared the oncologic outcomes between patients receiving RT + ADT and those receiving RT alone. Materials and Methods: We reviewed the records of patients diagnosed with prostate cancer between 1995 and 2011, including 93 patients who underwent salvage RT and 69 patients who underwent salvage RT + ADT. The ADT-free duration after withdrawal was calculated to verify testosterone recovery. Results: Presalvage prostate serum antigen (PSA) was the only significantly different characteristic between the 2 groups (p < 0.001). The ADT-free duration was greater than 6 months in >80% of patients. Presalvage PSA ≥0.6 ng/mL, pathologic stage ≥T3b, and RT + ADT were significantly associated with biochemical progression after salvage treatment. RT + ADT reduced biochemical progression in patients with seminal vesicle invasion or presalvage PSA ≥0.6 ng/mL (p = 0.001) compared to RT alone; biochemical progression-free probability was unchanged in seminal vesicle noninvasive prostate cancer patients with presalvage PSA <0.6 ng/mL (p = 0.541). Conclusions: RT + ADT reduced the risk of biochemical progression after salvage treatment in patients with seminal vesicle invasion or presalvage PSA ≥0.6 ng/mL, but had no effect in patients with seminal vesicle noninvasive disease and presalvage PSA <0.6 ng/mL.