Presentation Authors: Reith Sarkar, J Parsons*, John Einck, Arno Mundt, A Karim Kader, Christopher Kane, Paul Riviere, Rana McKay, James Murphy, Brent Rose, La Jolla, CA
Introduction: The safety of testosterone replacement therapy in men who have undergone radiation therapy (RT) for localized prostate cancer remains undefined.
Methods: In a large national cohort, the Veterans Affairs Informatics and Computing Infrastructure, we identified node-negative and non-metastatic prostate cancer patients diagnosed between 2001-2015 treated with RT. We excluded patients for missing covariate and follow-up data. We then coded receipt of testosterone replacement after RP as a time-dependent covariate. Other covariates included: age, Charlson Comorbidity index, diagnosis year, body mass index, race, PSA, clinical T/N/M stage, Gleason score, and receipt of hormone therapy. Biochemical recurrence was defined as a post-RP PSAâ‰¥ 0.2. We evaluated prostate cancer-specific survival, overall survival, and biochemical recurrence free survival using multivariable Cox regression.
Results: Our cohort included 41,544 patients, of whom 544 (1.3%) received testosterone replacement after RT. There were no differences in Charlson comorbidity, clinical T stage, median pre-treatment PSA or Gleason score between treatment groups. Testosterone patients were more likely to be of younger age, non-black, have a lower median post-treatment PSA nadir (0.1 vs. 0.2; p < 0.001), have higher BMI, and have used hormone therapy (46.7% vs 40.3%; p=0.003). Median duration of ADT usage was equivalent between treatment groups (testosterone: 185 days vs. non-testosterone: 186 days, p=0.77). The median time from RT to TRT was 3.52 years. After controlling for differences in covariates between treatment groups, we found no difference in prostate cancer specific mortality (HR 1.02; 95% CI 0.62-1.67; p=0.95), overall survival (HR 1.02; 95% CI 0.84-1.24; p=0.86), non-cancer mortality (HR 1.02; 95% CI 0.82-1.27; p=0.86) biochemical recurrence free survival (HR 1.07; 95% CI 0.90-1.28; p=0.45).
Conclusions: To our knowledge, this population-based cohort is the largest comparative analysis to date of testosterone therapy after RT. These data suggest that testosterone replacement is safe in patients who have undergone definitive management of localized prostate cancer with RT.