Pro-inflammatory diet predicts poorer survival in bladder cancer: Results from the bladder cancer prognosis programme

Bladder cancer (BC) is a global health burden, with an estimated 614,000 new cases and 220,000 deaths in 2022. While diet influences BC progression, the association between dietary inflammatory potential and BC prognosis remains unclear. This study investigated the association using the empirical dietary inflammatory pattern (EDIP) score in the Bladder Cancer Prognosis Programme (BCPP) cohort.

We included 1016 newly diagnosed BC patients (2005-2011) and assessed baseline and 3-month post-treatment EDIP scores using food frequency questionnaires. Multivariate Weibull regression models analyzed the associations between pre- and post-treatment EDIP and its dynamic changes with progression-free survival (PFS), overall survival (OS) and cancer specific survival (CSS).

A higher baseline EDIP score (more pro-inflammatory diet) was significantly associated with poorer outcomes in muscle-invasive BC (MIBC) patients (PFS: HR_{continuous EDIP}= 1.82, 95% CI: 1.11-3.00; OS: HR_{continuous EDIP}= 2.03, 95% CI: 1.21-3.41) and those aged >70 years (PFS: HR _{Q5 vs Q1}= 1.51, 95% CI: 1.06-2.17; OS: HR _{Q5 vs Q1}= 1.99, 95% CI: 1.26-3.13). Post-treatment EDIP alone showed no significant associations with BC prognosis. However, in non-muscle-invasive BC (NMIBC) patients, a shift from low to high post-treatment EDIP increased poor PFS risk (HR_Low/High= 1.57, 95% CI: 1.06-2.32), and persistently high EDIP elevated poor OS risk (HR_High/High= 2.02, 95% CI: 1.03-3.97) versus consistently low EDIP. No significant EDIP-related associations with CSS were observed.

Pro-inflammatory diets at diagnosis may worsen PFS and OS in MIBC patients and those aged >70 years. Dynamic post-treatment EDIP changes may impact NMIBC prognosis, highlighting the need for personalized dietary strategies tailored to BC subtype and age to improve survival.