Androgen deprivation therapy does not impact cause-specific or overall survival in high-risk prostate cancer treated with brachytherapy and supplemental external beam

Abstract

15578 Background: To determine cause-specific (CSS), biochemical progression-free (bPFS) and overall survival (OS) in high risk prostate cancer patients undergoing brachytherapy with or without supplemental therapies. Methods: From April 1995 through July 2002, 204 patients with high risk prostate cancer (Gleason score = 8 and/or PSA > 20 ng/mL and/or clinical stage = T2c) underwent brachytherapy with or without supplemental therapies. Of the 204 patients, 193 (94.6%) received supplemental XRT and 119 (58.3%) received ADT (ADT = 6 months n=40 and ADT > 6 months n = 79). Median follow-up was 7.0 years. All patients were implanted at least 4 years prior to analysis. BPFS was defined by a PSA = 0.40 ng/mL after nadir. Multiple clinical, treatment and dosimetric parameters were evaluated for the impact on survival. Results: The ten-year CSS, bPFS and OS were 88.9%, 86.6% and 68.6%, respectively. A statistically significant difference in bPFS was discerned between hormone naïve, ADT = 6 months and ADT > 6 month cohorts (79.7% vs. 95.0% vs. 89.9%, p= 0.032). ADT did not impact CSS (94.0% vs. 87.1%, p=0.983 ) or OS (65.2% vs. 70.3%, p = 0.713). For bPFS patients, the median post-treatment PSA was < 0.04 ng/mL. A Cox linear regression analysis demonstrated that Gleason score was the best predictor of CSS while percent positive biopsies and duration of ADT best predicted for bPFS. OS was best predicted by Gleason score and diabetes. Thirty-eight patients have died with 26 of the deaths due to cardiovascular/pulmonary disease or second malignancy. Eleven patients have died of metastatic prostate cancer. Conclusions: Androgen deprivation therapy improved 10-year bPFS without statistical impact on CSS or OS. Death as a result of cardiovascular/pulmonary disease and second malignancies were more than twice as common as prostate cancer deaths. Strategies to improve cardiovascular health should positively impact overall survival. No significant financial relationships to disclose.