Pretreatment Body Mass Index (BMI) as an Independent Prognostic Factor in Nasopharyngeal Carcinoma Survival: A Systematic Review and Meta-Analysis

We performed a meta-analysis to investigate the association between pretreatment body mass index (BMI) and prognosis of nasopharyngeal carcinoma (NPC). Case-control and cohort studies were searched from PubMed, Web of Science, EMBASE, and CNKI databases. Pooled hazard ratios (HR) with 95% confidence intervals (CI) for overall survival (OS) or distant metastasis-free survival (DMSF) were used to estimate the prognostic value. Bias in the included studies was evaluated using funnel plots. The results showed that compared with normal weight patients, the estimated HR of OS was 1.54 (95% CI: 1.25-1.90; P < 0.05) for underweight, 0.63 (95% CI: 0.48-0.83; P < 0.05) for overweight, and 0.67 (95% CI: 0.41-1.08; P = 0.102) obese patients. We also found that compared with normal-weight patients, the estimated HR of DMFS was 1.63 (95% CI: 1.38-1.92; P < 0.05) for underweight, 0.83 (95% CI: 0.61-1.13; P = 0.244) for overweight, and 0.60 (95% CI: 0.39-0.92; P < 0.05) for patients with obesity. BMI is an independent prognostic factor for NPC survival. Being underweight before treatment was associated with poorer OS and DMFS in patients with NPC. Neither overweight nor obesity before treatment has an unfavorable effect on NPC survival.