No Link Between BMI and NMIBC Recurrence, Stage or Grade Progression

Previous research has suggested that increasing body mass index (BMI) serves as a risk factor for the development of bladder cancer, independent of confounding variables. Recent research has assessed the impact of BMI category on non-muscle invasive bladder cancer (NMIBC) recurrence, stage progression, and grade progression.

A total of 457 patients with NMIBC were included in the study. Each patient was categorized into one of three groups based on their BMI: normal weight, overweight, or obese.

Disease recurrence was classified as any histologically proven bladder cancer on subsequent transurethral resection of bladder tumor (TURBT), and progression was classified as upgrading from low to high grade, upstaging to pT1 from pTa, or to muscle-invasion from pT1 disease.

Of the patients analyzed, 135 (29.5%) had normal weight, 192 (42.6%) were overweight, and 130 (28.4%) were obese. The median BMI was 27.1 (24.4-30.7) Kg/m2. No significant difference was found in time to recurrence, stage progression, and grade progression in each BMI category (P<.05), and no increased risk was observed in each category (obesity recurrence HR: 1.067, CI 95%: 0.783-1.453; obesity stage progression HR: 1.315, 95% CI: 0.635-2.724; obesity grade progression HR: 0.586, 95% CI: 0.195-1.760).

This new research shows no link between patient BMI and NMIBC recurrence, stage progression, or grade progression, pointing to a need to determine other potential risk factors that could better improve NMIBC risk stratification. Further studies are warranted to validate these results and find other predictors of NMIBC outcomes.