BMI Is a Risk Factor for Colorectal Cancer Mortality

Background: The relationship between dietary and lifestyle risk factors and long-term mortality from colorectal cancer is poorly understood. Several factors, such as obesity, intakes of red meat, and use of aspirin, have been reported to be associated with risk of colorectal cancer mortality, though these findings have not been replicated in all studies to date. Methods: In the Minnesota Colon Cancer Control Study, 46,551 participants 50–80 years old were randomly assigned to usual care (control) or annual or biennial screening by fecal occult blood testing. Colon cancer mortality was assessed after 30 years of follow-up. Dietary intake and lifestyle risk factors were assessed by questionnaire at baseline. Results: Age [hazard ratio (HR) 1.09; 95% CI 1.07, −1.11], male sex (HR 1.25; 95% CI 1.01, 1.57), and higher body mass index (BMI) (HR 1.03; 95% CI 1.00–1.05) increased the risk of CRC mortality, while undergoing screening for CRC was associated with a reduced risk of colorectal cancer mortality (HR 0.76; 95% CI 0.61–0.94 and 0.67; 95% CI 0.53–0.83 for biennial and annual screening, respectively). Intakes of grains, meats, proteins, coffee, alcohol, aspirin, fiber, fruits, and vegetables were not associated with colorectal cancer mortality. Conclusions: Our study confirms the relationship between BMI and long-term colorectal cancer mortality. Modulation of BMI may reduce risk of CRC mortality.