OBESITY is associated with an increased risk for numerous different cancer types, including gastrointestinal cancers. A retrospective cohort secondary analysis of the National Cancer Institute (NCI) PLCO Cancer Screening Trial prompted further investigation into the mechanistic role of obese BMI in carcinogenesis.
The research objective was to evaluate the correlation between gastrointestinal cancer risk and BMI, using a large population-based study. The study revealed that overweight and obese BMI during adulthood was associated with increased risk for colorectal cancer and non-colorectal gastrointestinal cancers, and aspirin use failed to modify the association.
The research team investigated the association between BMI and aspirin use, and the risk of colorectal and non-colorectal gastrointestinal cancer among 135,161 participants (median age: 60 years; 50% female). They used Cox proportional hazards regression modelling to assess the association between BMI and cancer, and the association between cancer risk and change in BMI at varying ages was explored. Additionally, an investigative analysis was performed to assess gastrointestinal cancer risk among aspirin users. The primary outcomes were the diagnoses of colorectal cancer and non-colorectal gastrointestinal cancer.
The results showcased an association between increased colorectal cancer risk and overweight BMI in early adulthood, middle adulthood, and later adulthood, as well as a correlation between increased colorectal cancer risk and obese BMI in middle adulthood and late adulthood. The researchers observed similar associations between gastrointestinal cancer and non-colorectal gastrointestinal cancer risk and BMI during middle and later adulthood. Moreover, maintaining overweight or obese BMI, or increasing BMI to overweight or obese during later adulthood showcased an association with increased colorectal cancer risk.
Overweight and obese BMI appeared correlated with an increased risk for colorectal cancer and non-colorectal gastrointestinal cancer among participants who used aspirin three or more times per week. This suggests that aspirin may not be effective for prevention in those who are overweight or obese. Although the study is limited due to being a secondary analysis of a randomised controlled trial, the results propose that being overweight or obese during several phases of life may heighten risk gastrointestinal cancers.
