Post-diagnostic Lifestyle and Mortality of Cancer Survivors: Results from a Prospective Cohort Study

Objective: Lifestyle factors after cancer diagnosis could influence cancer survival. This study aimed to investigate the joint effects of smoking, physical activity, alcohol consumption, diet and sleep duration on all-cause, cancer and non-cancer mortality of cancer survivors in UK biobank. Methods: The follow-up period concluded in December 2021, with post-diagnostic lifestyle factors assessed at baseline. A lifestyle score ranging from 0 to 5 was assigned based on adherence to the selected lifestyle factors. The study employed Cox regression models for hazard ratios (HRs) and Kaplan-Meier for survival rates, with stratified and sensitivity analyses to assess the robustness of our findings under various assumptions. Results: During a median follow-up of 12.7 years, 5652 deaths were documented from 34,184 cancer survivors. Compared to scoring 0-1, the HRs (95% CIs) for all-cause mortality with lifestyle scores of 2, 3, 4, and 5 were 0.70 (95% CI: 0.64, 0.76), 0.57 (0.52, 0.62), 0.50 (0.45, 0.54) and 0.43 (0.38, 0.48), respectively. Specific cancer types, particularly digestive, breast, female reproductive, non-solid, and skin cancers, showed notable benefits from adherence to healthy lifestyle, with the HRs of 0.55 (0.39, 0.79), 0.54 (0.42, 0.70), 0.32 (0.19, 0.53), 0.58 (0.39, 0.86), and 0.36 (0.28, 0.46) for lifestyle score of 5, respectively. Stratified analyses indicated the association was particularly significant among those with normal/lower BMI and higher Townsend Deprivation Index (P-interaction = 0.001 and < 0.001, respectively). Conclusions: Healthier lifestyles were significantly linked with reduced mortality among cancer survivors. These findings highlight the need for adherence to healthy lifestyle habits to improve survival.