Impact of Postdiagnosis Health Behaviors and Behavior Changes on Prognosis in Colorectal Cancer Patients: Evidence From Real-World Data.

BACKGROUND: Colorectal cancer (CRC) is a prevalent cancer worldwide, but encouraging healthier lifestyle choices among survivors may improve their prognosis. We aimed to evaluate health habits adopted after diagnosis and their impact on prognosis. METHODS: For this population-based retrospective cohort study, we used data from the Cancer Public Library Database (CPLD), which consists of four major population-based public sources in Korea with cancer patients diagnosed between 2012 and 2019. Information on anthropometric measures, physical activity, alcohol consumption, and smoking status before and after cancer diagnosis was used. Hazard ratios (HRs) for all-cause deaths with 95% confidence intervals (CIs) were estimated via the Cox proportional hazards model. RESULTS: Among the 7553 CRC patients, postdiagnosis physical activity was significantly related to decreased risk of death among those who were diagnosed with stage I or III CRC (p for trend < 0.05). The analysis of 4588 patients revealed that increased physical activity (stage I: adjusted HR [aHR] = 0.60, 95% CI = 0.29-1.22; stage II: aHR = 0.86, 95% CI = 0.49-1.52; stage III: aHR = 0.60, 95% CI = 0.36-0.99) or smoking cessation (stage I: aHR = 0.81, 95% CI = 0.28-2.35; stage II: aHR = 0.36, 95% CI = 0.16-0.81; stage III: aHR = 0.89, 95% CI = 0.42-1.87), were associated with poor prognosis compared to those who consistently remained physically inactive or continued to smoke. CONCLUSION: The present study provides compelling evidence on the benefits of increased physical activity and smoking cessation after CRC diagnosis for improved survival.