Aim: To evaluate the association of body mass index (BMI) with the overall survival of pancreatic ductal adenocarcinoma (PDAC) patients.
Methods: A retrospective analysis of PDAC patients diagnosed in the National Cancer Center of China between January 1999 and December 2014 was performed. These patients were categorized into four BMI groups (< 18.5, 18.5-22.9, 23-27.4 and ≥ 27.5 kg/m2). χ2 tests for comparison of the proportions of categorical variables, and Student's t-test or Mann-Whitney test for continuous variables were employed. Survival analysis was performed with the Kaplan-Meyer method. Their HRs of mortality and 95%CIs were estimated using the Cox proportional hazards model.
Results: With a median age of 59.6 years (range: 22.5-84.6 years), in total 1783 PDAC patients were enrolled in this study. Their mean usual BMI was 24.19 ± 3.53 for the whole cohort. More than half of the patients (59.3%) experienced weight loss during the disease onset and progression. Compared with healthy-weight individuals, newly diagnosed patients who were overweight or obese had more severe weight loss during their disease onset and progression (P < 0.001). Individuals who were overweight or obese were associated with positive smoking history (P < 0.001). A significant difference in comorbidity of diabetes (P = 0.044) and coronary artery disease (P < 0.001) was identified between high BMI and normal-weight patients. After a median follow-up of 8 mo, the survival analysis showed no association between BMI and the overall survival (P = 0.90, n = 1783). When we stratified the whole cohort by pancreatic cancer stage, no statistically significant association between BMI and overall survival was found for resectable (P = 0.99, n = 217), unresectable locally advanced (P = 0.90, n = 316) and metastatic patients (P = 0.88, n = 1250), respectively. The results did not change when we used the BMI at diagnosis.
Conclusion: Our results showed no significance of BMI for the overall survival of PDAC patients.
Keywords: Body mass index; Overweight; Pancreatic cancer; Smoking history; Survival analysis.