Association between obesity and bladder cancer recurrence: A meta-analysis

The association between obesity and bladder cancer prognosis is not well-defined. This meta-analysis was performed to explore whether obesity is related to overall survival (OS) and bladder cancer recurrence. Relevant English-language studies were identified by searching PubMed® up to November 1, 2017. We pooled the hazard ratios (HR) and 95% confidence intervals (CIs) using a random effect model. Dose-response relationship, subgroup and sensitivity were also analyzed. Eleven studies were included. Recurrence rate of bladder cancer was significantly greater in obese (HR = 1.76, 95% CI: 1.36–2.28) vs normal weight patients. Stratification analysis showed that females had higher recurrence risk than males (HR = 1.17, 95% CI: 1.05–1.31). Obesity was not significantly associated with bladder cancer OS (HR = 1.21, 95% CI: 0.97–1.52). Dose-response relationship analysis revealed a linear association between BMI and risk of recurrence. Each one kg/m2 increase in BMI was related to a 1.3% increased risk of bladder cancer recurrence (HR = 1.01, 95% CI = 1.01 to 1.02). This meta-analysis revealed that obesity may be a risk factor for bladder cancer recurrence. •A tight relationship between obesity and bladder cancer prognosis is proposed.•Obese patients get higher rate of bladder cancer recurrence compared to patients with normal weight.•Obesity is not associated with postoperative survival of bladder cancer.