Joint Effects of Low Body Mass Index and Alcohol Consumption on Developing Esophageal Squamous Cell Cancer: a Korean Nationwide Population-Based Cohort Study.

Objective: In Korea, 95% of esophageal cancer (EC) was the squamous cell-type. We sought to determine the combined risk of alcohol consumption on developing esophageal squamous cell carcinoma (ESCC) in pre-diagnostic underweight subjects using Korean national data. Methods: We analyzed the clinical data from a total of 264,084 individuals aged 40 years or older, who received healthcare checkups arranged by the national insurance program, between 2003 and 2008 in Korea. Cox proportional hazards regression was used after adjusting confounding factors. Result: Newly diagnosed 278 EC was identified using the claims data during a median follow-up duration of 7.9 years. It was determined that underweight and obesity-compared with normal weight-were significantly associated with 73% increased risk and 30% decreased risk of EC, respectively. Weight gain reduced the risk of EC. Alcohol consumption increased risk for EC in a dose-dependent manner. Heavy alcohol consumption in individuals with underweight increased the risk of developing EC dramatically. Conclusion: Underweight was a risk factor for ESCC and alcohol consumption raised the risk synergistically with low BMI. Achieving normal range of BMI could reduce the risk of ESCC.