Men and women with a large waist circumference and a large waist-to-hip ratio (WHR) have an increased risk of developing colon cancer. In contrast, only in men is a high body mass index (BMI) clearly associated with a higher colon cancer risk.
However, there is no relation between the body measures of the investigation and rectal cancer risk. These results from the European-wide EPIC study (European Prospective Investigation into Cancer and Nutrition) were published on July 5th by Tobias Pischon of the German Institute of Human Nutrition Potsdam-Rehbrücke (DIfE) and his colleagues in the Journal of the National Cancer Institute.
“Our results support the hypothesis that abdominal body fat is especially important for development of colon cancer. This agrees with our observation that BMI is rather inappropriate for predicting colon cancer in women because the relation between BMI and waist circumference is not as close as in men. This is probably because men gain weight primarily by increasing abdominal body fat, whereas in women, body fat normally also accumulates in other parts of the body”, says Heiner Boeing, head of EPIC Potsdam. “Why increased abdominal fat raises the risk of colon cancer is currently unknown. The insulin resistance associated with abdominal obesity and the resulting increase in circulating insulin levels may possibly play a role. Other potential mediators are leptin and adiponectin. We are currently examining within EPIC these and other biomarkers for their possible association with colorectal cancer.”
In addition to DIfE, the Deutsche Krebsforschungszentrum in Heidelberg is the second German study center involved in EPIC.
The researchers examined in 368,277 EPIC participants the associations between various body measures and the risk of colon and rectal cancer. The analysis is based on a circa 6-year follow-up during which 984 participants developed colon cancer and 586 rectal cancer.
The epidemiologists came to the following conclusions: Women with a WHR over 0.85 had a 52 percent higher risk of colon cancer than those with a WHR under 0.73. Similar values were observed in men, whose colon cancer risk increased by 51 percent from the group (quintile) with the lowest WHR (<0.89) to the group with the highest WHR (=0.99).