Overweight Colorectal Cancer Patients Could Fare Better

Although higher body mass indexes (BMIs) are associated with a number of health risks, the results of a recent study suggest that overweight patients who develop colorectal cancer may have a better prognosis than those with a healthy weight. After adjusting the data to account for socioeconomic, demographic, disease severity, prediagnosis BMI, smoking, and other factors, the researchers found that patients who were in the high-overweight category (BMI of 28-30) at diagnosis had a 48% lower mortality risk overall and a 55% lower mortality risk related to colorectal cancer compared with patients whose weight was considered to be low to normal (BMI of 18.5-23). However, patients who were underweight (BMI below 18.5) or obese (BMI ≥35) at diagnosis were found to have an elevated mortality risk compared with patients in the low-normal-weight category.

The study authors noted that further research is needed to better understand the mechanisms responsible for this apparent paradox. “The current findings, and previous and ongoing research on the obesity paradox, suggest that recommendations for the ideal weight range associated with the best outcomes after a cancer diagnosis may not be the same as the ideal weight range to prevent cancer,” said senior author Bette J. Caan, DrPH, in a press release. “And just as treatment differs by cancer, ideal weight recommendations may vary according to cancer site.”