First-year weight loss with androgen-deprivation therapy increases risks of prostate cancer progression and prostate cancer-specific mortality: results from SEARCH.

PURPOSE: We aimed to study the associations between androgen-deprivation therapy (ADT)-induced weight changes and prostate cancer (PC) progression and mortality in men who had undergone radical prostatectomy (RP). METHODS: Data from the Shared Equal Access Regional Cancer Hospital (SEARCH) cohort were used to study the associations between weight change approximately 1-year post-ADT initiation and metastases, castration-resistant prostate cancer (CRPC), all-cause mortality (ACM), and PC-specific mortality (PCSM) in 357 patients who had undergone RP between 1988 and 2014. We estimated hazard ratios (HR) and 95% confidence intervals (95% CI) using covariate-adjusted Cox regression models for associations between weight loss, and weight gains of 2.3 kg or more, and PC progression and mortality post-ADT. RESULTS: During a median (IQR) follow-up of 81 (46-119) months, 55 men were diagnosed with metastases, 61 with CRPC, 36 died of PC, and 122 died of any cause. In multivariable analysis, weight loss was associated with increases in risks of metastases (HR 3.13; 95% CI 1.40-6.97), PCSM (HR 4.73; 95% CI 1.59-14.0), and ACM (HR 2.16; 95% CI 1.25-3.74) compared with mild weight gains of ≤ 2.2. Results were slightly attenuated but remained statistically significant in analyses that accounted for competing risks of non-PC death. Estimates for the associations between weight gains of ≥ 2.3 kg and metastases (HR 1.58; 95% CI 0.73-3.42), CRPC (HR 1.33; 95% CI 0.66-2.66), and PCSM (HR 2.44; 95% CI 0.84-7.11) were elevated, but not statistically significant. CONCLUSIONS: Our results suggest that weight loss following ADT initiation in men who have undergone RP is a poor prognostic sign. If confirmed in future studies, testing ways to mitigate weight loss post-ADT may be warranted.

Does Early Prostate Specific Antigen Doubling Time after Radical Prostatectomy, Calculated Prior to Prostate Specific Antigen Recurrence, Correlate with Prostate Cancer Outcomes? A Report from the SEARCH Database Group.

PURPOSE: Short prostate specific antigen doubling time following recurrence after radical prostatectomy portends a poor prognosis. Prostate specific antigen doubling time is traditionally calculated using prostate specific antigen values 0.2 ng/ml or greater. We determined whether early prostate specific antigen doubling time, calculated from the first detectable postoperative prostate specific antigen up to and including the first recurrence value, correlates with prostate cancer outcomes. MATERIALS AND METHODS: Cox models were used to examine the association between early prostate specific antigen doubling time and castration resistant prostate cancer, metastases, and all cause and prostate cancer specific mortality in 674 men who underwent radical prostatectomy between 1988 and 2014 and had a biochemical recurrence. Early prostate specific antigen doubling time was examined as a log transformed continuous and a categorical variable. RESULTS: After adjusting for multiple clinicopathological characteristics, log transformed early prostate specific antigen doubling time was not associated with any outcome. However, when early doubling time was categorized as 15 or greater, 9 to 14.9, 3 to 8.9 and less than 3 months, on multivariable analysis men with early doubling time less than 3 months were at increased risk for castration resistant prostate cancer (HR 6.20, p = 0.004), metastases (HR 5.26, p = 0.001), prostate cancer specific mortality (HR 5.06, p = 0.026) and all cause mortality (HR 1.63, p = 0.065) compared to those with an early doubling time of 15 months or greater. However, the association with all cause mortality was not significant. Those with an early prostate specific antigen doubling time of 3 to 8.9 months were at increased risk for castration resistant prostate cancer (HR 3.56, p = 0.015), all cause mortality (HR 1.67, p = 0.006) and prostate cancer specific mortality (HR 3.17, p = 0.044) but not metastases (p = 0.13). CONCLUSIONS: Early prostate specific antigen doubling time less than 9 months, calculated using prostate specific antigen values before and up to biochemical recurrence, is associated with an increased risk of castration resistant prostate cancer, metastases, and prostate cancer specific and all cause mortality among men with biochemical recurrence after radical prostatectomy. Early prostate specific antigen doubling time allows for risk stratification at biochemical recurrence and before prostate specific antigen doubling time is calculable, enabling these men to be referred for early aggressive secondary treatment and/or clinical trials.