Body mass index does not affect the survival of pancreatic cancer patients

To evaluate the association of body mass index (BMI) with the overall survival of pancreatic ductal adenocarcinoma (PDAC) patients.

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.

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.

Our results showed no significance of BMI for the overall survival of PDAC patients.