Life Expectancy in High-Grade Incidental Prostate Cancer Patients Versus Population-Based Controls According to Treatment Type.

Objective: To quantify the differences in 5-year overall survival (OS) between high-grade (Gleason sum 8-10) incidental prostate cancer (IPCa) patients and age-matched male population-based controls, according to treatment type: no active versus active treatment.

Materials and methods: We relied on the Surveillance, Epidemiology, and End Results (SEER) database (2004-2015) to identify not actively treated and actively treated high-grade IPCa patients. For each case, we simulated an age-matched male control (Monte Carlo simulation), relying on Social Security Administration Life Tables (2004-2020) with 5 years of follow-up. Additionally, we relied on Kaplan-Meier plots to display OS for each treatment type. Multivariable Cox regression models were fitted to predict overall mortality (OM).

Results: Of 564 high-grade IPCa patients, 345 (61%) were not actively treated versus 219 (39%) were actively treated, either with radical prostatectomy or radiotherapy. Median OS was 3 years for not actively treated high-grade IPCa patients, with OS difference at 5 years follow-up of 27% relative to their age-matched male population-based controls (37% vs. 64%). Median OS was 8 years for actively treated high-grade IPCa patients, with OS difference at 5 years follow-up of 6% relative to their age-matched male population-based controls (68% vs. 74%). In the multivariable Cox regression model, active treatment independently predicted lower OM (hazard ratio = 0.6; 95% confidence interval = 0.4-0.8; p < 0.001).

Conclusion: Relative to Life Tables' derived age-matched male controls, not actively treated high-grade IPCa patients exhibit drastically worse OS than their actively treated counterparts. These observations may encourage clinicians to consider active treatment in newly diagnosed high-grade IPCa patients.