Prediagnostic adult body mass index change and esophageal adenocarcinoma survival

Background: We examined whether body mass index (BMI) changes in adulthood, prior to disease onset, are associated with overall survival among esophageal adenocarcinoma patients. Methods: We included 285 histologically confirmed patients with a complete baseline BMI questionnaire. Using extended Cox regression models, we obtained adjusted hazard ratios (HRs) for the associations between overall survival and BMI at diagnosis, BMI 6 months before diagnosis, self-reported average adult BMI, and ΔBMI (BMI 6 months before diagnosis minus average adult BMI), categorized into tertiles <0 kg/m² (BMI loss), ≥0 and <1.25 kg/m² (stable BMI), and ≥1.25 kg/m² (BMI gain). We also assessed interaction between ΔBMI and average adult BMI (≥ kg/m² versus <27.5 kg/m²) with overall survival. Results: Body mass index at diagnosis >25 and <35 kg/m² was associated with better overall survival. Compared to patients with stable BMI in adulthood, patients who gained BMI throughout adulthood had 1.68 times the all-cause hazard of death (95% CI: 1.17-2.43; P <.01), independent of diagnosis BMI and percent weight loss 6 months before diagnosis. Compared to patients with average adult BMI < 27.5 who maintained stable adult BMI, patients with average adult BMI ≥ 27.5 kg/m² who gained BMI had the worst survival (HR = 3.05; 95% CI 1.62-5.72; P <.01). Conclusion: Body mass index gain in adulthood is associated with poor overall survival, and maintaining a normal body weight throughout adulthood is associated with the best overall survival among esophageal adenocarcinoma patients, independent of BMI at diagnosis.