Surveillance Versus Treatment for Favorable Intermediate-Risk Prostate Cancer and Mortality-Risk.

[BACKGROUND] Active surveillance (AS) is the preferred management approach for patients with low-risk prostate cancer (PC); yet whether younger patients with favorable-intermediate-risk (FIR) PC experience increased mortality-risk when electing AS remains unknown. We evaluated all-cause, PC-specific, and non-PC-specific mortality (ACM, PCSM, and non-PCSM) in younger patients with FIR PC managed with either AS/watchful-waiting (WW) or immediate definitive treatment, stratified by race.

[METHODS] We conducted a retrospective cohort study using SEER data (2010-2020). Patients included were < 60 years-old with FIR PC. The primary outcome was ACM, secondary outcomes PCSM and non-PCSM. Multivariable Cox and Fine-Gray competing-risk regressions were used, adjusting for known prognostic factors. Interaction by race (White vs underrepresented minority [URM]) was explored. Statistical significance was set at p < 0.025 (Bonferroni-adjusted).

[RESULTS] Among 3,832 patients, 127 died (3.31%), including 18 of the 127 deaths from PC (14.17%). Initial treatment with RP/RT did not significantly reduce ACM or non-PCSM compared to AS/WW in White (ACM AHR, 0.92; 95% CI, 0.44-1.94; non-PCSM AHR, 1.36; 95% CI, 0.53-3.46) or URM patients (ACM AHR, 0.68; 95% CI, 0.33-1.43; non-PCSM AHR, 1.04; 95% CI, 0.44-2.44). However, after adjustment for multiplicity RP/RT significantly reduced PCSM-risk compared to AS/WW in URM (AHR, 0.03; 95% CI, 0.00-0.48; p = 0.01), but not in White patients (AHR, 0.21; 95% CI, 0.05-0.88; p = 0.03) although the median follow-up was 6.5-months longer in URM patients undergoing AS/WW compared to RP/RT.

[CONCLUSIONS] Early mortality-risks were similar and low in patients age < 60 years with FIR PC managed with AS/WW compared to RP/RT, irrespective of race.