Adherence to lifestyle recommendations after non-muscle invasive bladder cancer diagnosis and risk of recurrence

Background: Patients with non-muscle invasive bladder cancer (NMIBC) are at a high risk of tumor recurrence. It has not been previously investigated if adherence to cancer prevention recommendations lowers the risk of recurrence.Objectives: We examined whether the standardized lifestyle score measuring adherence to the 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations was associated with the risk of recurrence and progression among patients with NMIBC.Methods: The study population included patients diagnosed with primary NMIBC between 2014 and 2017 from the prospective cohort UroLife. Lifestyle was assessed at baseline (n = 979; reflecting the prediagnosis period) and 3-mo postdiagnosis (n = 885). The standardized 2018 WCRF/AICR score was constructed based on recommendations for body weight, physical activity, diet, and alcohol intake. We computed multivariable-adjusted HRs and 95% CIs using Cox proportional hazard regression models.Results: During a median follow-up time of 3.7 y, 320 patients developed >1 recurrence(s) and 49 experienced progression. Patients in the highest compared with the lowest tertile of postdiagnosis WCRF/AICR scores had a lower risk of first bladder cancer recurrence (HR: 0.74; 95% CI: 0.56, 0.98). No associations were observed for multiple recurrences (HR: 0.90; 95% CI: 0.70, 1.15) or for the baseline score with either first (HR: 1.07; 95% CI: 0.82, 1.40) or multiple recurrences (HR: 1.04; 95% CI: 0.82, 1.31). Improving lifestyle after diagnosis (per 1-point increase) was not significantly associated with the risk of first or multiple recurrence(s) (HR: 0.87; 95% CI: 0.74, 1.02; HR: 0.93; 95% CI: 0.80, 1.08, respectively). No associations were observed for bladder cancer progression, but the power was limited. Conclusions: Better adherence to the WCRF/AICR cancer prevention recommendations 3 mo after NMIBC diagnosis, but not before diagnosis, is associated with a decreased risk of first bladder cancer recurrence. More studies evaluating postdiagnosis lifestyles are needed to provide solid support for lifestyle recommendations for cancer survivors.