Fruit and vegetable intake and the risk of recurrence in patients with non-muscle invasive bladder cancer:a prospective cohort study

INTRODUCTION: There is some evidence that greater consumption of fruit and vegetables decreases the risk of bladder cancer. The role of fruit and vegetables in bladder cancer recurrence is still unknown.OBJECTIVE: The role of total fruit and vegetable intake in relation to the risk of developing bladder cancer recurrence in a prospective cohort study.METHODS: 728 patients with non-muscle invasive bladder cancer (NMIBC), who completed self-administrated questionnaires on fruit and vegetable intake at time of diagnosis (over the year before diagnosis) and 1 year after diagnosis, were included. Hazard ratios and 95% confidence intervals were calculated by multivariable Cox regression for developing recurrent bladder cancer in relation to fruit and vegetable intake.RESULTS: During 2,051 person-years of follow-up [mean (SD) follow-up 3.7 (1.5) years], 241 (33.1%) of the included 728 NMIBC patients developed a recurrence of bladder cancer. The sum of total fruit and vegetables before diagnosis was not related to a first bladder cancer recurrence (HR 1.07; 95% CI 0.78-1.47, p = 0.66). No association was found between greater consumption of fruit and vegetables over the year before diagnosis and the risk of developing multiple recurrences of bladder cancer (HR 1.02; 95% CI 0.90-1.15, p = 0.78). Among the remaining 389 NMIBC patients who reported on fruit and vegetable intake 1 year after diagnosis, no association was found between greater consumption of fruit and vegetables and a first recurrence of bladder cancer (HR 0.65; 95% CI 0.42-1.01, p = 0.06) nor with multiple recurrences of bladder cancer (HR 1.00, 95% CI 0.85-1.18, p = 1.00). Similar results were obtained when investigating the association between total intakes of fruit and vegetables separately and bladder cancer recurrence.CONCLUSION: Results from this study did not indicate a protective role for total fruit and vegetables in the development of a recurrence of NMIBC.