Purpose: We retrospectively evaluated the benefit of neoadjuvant androgen deprivation therapy administered before salvage external beam radiation treatment in patients with biochemical failure following retropubic radical prostatectomy (RRP).
Materials and methods: A total of 81 patients were treated with neoadjuvant androgen deprivation therapy before salvage external beam radiation treatment because of an increased prostate specific antigen (PSA) level following RRP. Preoperative, pathological, postoperative, and pre-salvage treatment parameters and radiation therapy dosage were examined for influence on outcome. Biochemical failures after RRP or salvage external beam radiation treatment were defined as a PSA greater than 0.3 ng/ml on 2 consecutive measurements. Median radiation dose delivered was 60 Gy. Neoadjuvant androgen deprivation therapy consisted of a 3 month injection of a luteinizing hormone releasing hormone analogue. Median followup was 38 months (range 12 to 102) after completion of external beam radiation treatment and 91 months (range 20 to 163) after radical prostatectomy.
Results: The actuarial free biochemical failure rates at 3 and 5 years were 75% and 50%, respectively. Two patients (2%) died of prostate cancer. Significant predictors of response to salvage external beam radiation treatment on a univariate analysis were a pre-radiation serum PSA less than 1 ng/ml and a pathological Gleason score less than 7. However, only pre-radiation PSA remained statistically significant on a multivariable analysis.
Conclusions: External beam radiation with neoadjuvant androgen deprivation therapy is a viable option for patients with an increasing post-prostatectomy serum PSA. The most powerful predictor of biochemical failure was pre-radiation serum PSA.