Impact of Smoking on Overall and Cancer-Specific Mortality in Prostate Cancer: Elevated Risks in Older and Early-Stage Patients—A Population-Based Study

Prostate cancer (PCa) ranks sixth in cancer mortality among Taiwanese men, with smoking rates remaining high despite the 2009 Tobacco Hazards Prevention Act. This study used the Taiwan Cancer Registry to evaluate smoking’s impact on PCa mortality, providing important information for healthcare strategies and patient management. From 2011 to 2017, 23,107 PCa patients were analyzed, with 7164 smokers and 15,943 non-smokers. The baseline characteristics, clinical stages, comorbidities, and treatment modalities were all included to estimate overall and cancer-specific mortality using the Cox regression model and Kaplan–Meier analysis. The stratified analysis of clinical stage and age group was also estimated. Our study found an association between smoking and increased overall and cancer-specific mortality in PCa patients. Although smokers over 60 had higher risks of overall mortality than non-smokers, cancer-specific mortality did not show significant differences in any age group. Smokers had higher overall mortality than non-smokers across all clinical stages, but cancer-specific mortality was significantly raised only in early-stage cases. In conclusion, smoking is associated with higher overall mortality in PCa patients, with a significant increase in cancer-specific mortality in early-stage cases. Therefore, active smoking management is critical for clinical urologists, particularly in the treatment of early-stage patients.