Life expectancy in rare histological prostate cancer subtypes

Survival differences in rare histological prostate cancer (PCa) subtypes relative to age-matched population-based controls are unknown. Within Surveillance, Epidemiology, and End Results database (2004-2020), newly diagnosed (2004-2015) PCa patients were identified. Relying on the Social Security Administration Life Tables (2004-2020) with 5 years of follow-up, age-matched population-based controls (Monte Carlo simulation) were simulated for each patient. Kaplan-Meier analyses addressed survival rates. Of 582,220 patients, 580,368 (99.68%) harbored acinar, 867 (0.15%) ductal, 534 (0.09%) neuroendocrine, 368 (0.07%) mucinous, and 83 (0.01%) signet ring cell carcinoma. The metastatic stage was most prevalent in neuroendocrine (62%). In the localized stage, the overall survival difference at 5 years of follow-up was greatest in neuroendocrine (22% vs. 72%), signet ring cell (78% vs. 84%), and ductal carcinoma (71% vs. 77%). In the locally advanced stage, overall survival difference was greatest in neuroendocrine (16% vs. 79%), signet ring cell (75% vs. 91%), ductal (78% vs. 84%), and mucinous carcinoma (84% vs. 90%). In the metastatic stage, the overall survival difference was greatest in neuroendocrine (3% vs. 81%), mucinous (26% vs. 84%), and acinar carcinoma (27% vs. 85%). Regardless of stage, neuroendocrine carcinoma patients exhibit the least favorable life expectancy compared with population-based controls. Conversely, all other rare histological PCa subtypes do not meaningfully affect life expectancy in localized or locally advanced stages, except for locally advanced signet ring cell adenocarcinoma.