Limited Changes in Lifestyle Behaviours after Non-Muscle Invasive Bladder Cancer Diagnosis

SIMPLE SUMMARY: Little is known about lifestyle behaviours following a diagnosis with non-muscle invasive bladder cancer. In this observational study, we aimed to investigate adherence to lifestyle recommendations and changes in lifestyle in 935 patients with non-muscle invasive bladder cancer in the first fifteen months after diagnosis. Second, we aimed to identify distinct trajectories of lifestyle change and their correlates. Each patient was assigned a score based on adherence to lifestyle recommendations focusing on diet, body mass index, and physical activity. We found that patients’ adherence to these lifestyle recommendations was low. Their overall lifestyle score remained constant up to fifteen months after diagnosis. Small to moderate changes in and different trajectories of single lifestyle behaviours were observed, with correlates differing per trajectory group. Given that there is considerable room for lifestyle improvement, effective strategies to support favourable lifestyle changes are needed. ABSTRACT: The aim of our study was to investigate adherence to lifestyle recommendations and lifestyle changes after diagnosis in patients with non-muscle invasive bladder cancer (NMIBC). Second, we aimed to identify distinct trajectories of lifestyle change and their correlates. We analysed data of 935 patients with NMIBC from a prospective cohort study at six weeks (evaluating pre-diagnostic lifestyle), three months, and fifteen months after diagnosis. An overall lifestyle score (range 0–7) was calculated based on the 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) recommendations focusing on diet, body mass index, and physical activity. Linear mixed models were used to analyse absolute lifestyle changes over time. Distinct trajectories of change were identified with latent class trajectory models. We found an overall lifestyle score of 3.3 which remained constant over time. The largest lifestyle changes were observed for the consumption of red and processed meat (−96 g/week) and fruit and vegetables (−38 g/day). Two to four trajectory groups were identified for each single lifestyle behaviour. Correlates differed per trajectory group. In conclusion, adherence to the WCRF/AICR recommendations was low. Small to moderate changes in and different trajectories of single lifestyle behaviours were observed. Effective strategies for lifestyle improvement are warranted.