Lifestyle Factors May Mitigate Colorectal Cancer Risk

Previous studies have suggested a causal role of lifestyle factors in colorectal cancer. Helene Kirkegaard, from the Danish Cancer Society (Denmark), and colleagues conducted a large-scale study to evaluate specific lifestyle factors and the degree to which health behaviors contribute to risk of colorectal cancer. The team enrolled 55,487 men and women, ages 50 to 64 years at the study’s start in 1993, when each completed a detailed lifestyle survey.  The subjects were followed through 2006, when data concerning colorectal cancer was obtained from the Danish Pathology Databank. The researchers found that if the study subjects had adhered to only one additional recommendation regarding physical activity, waist circumference, smoking, alcohol intake, or diet, an estimated 13% of cases could have been prevented.  The same research group then conducted a second study, randomizing 530 men and women to an active intervention designed for those with low literacy skills, or to a control group. Participants in the active intervention group received a booklet and DVD that reviewed the merits of colorectal screening and explained polyp removal ; control subjects received a consumer booklet that just outlined the data on bowel and other cancers, and provided relative risk statements.  The team found that those who received the decision aid subsequently were rated as having greater total knowledge, and 22% more of those in the active intervention group made informed choices. The researchers urge that: “Adherence to the recommendations for physical activity, waist circumference, smoking, alcohol intake, and diet may reduce colorectal cancer risk considerably, and in this population 23% of the cases might be attributable to lack of adherence to the five lifestyle recommendations. The simple structure of the lifestyle index facilitates its use in public health practice.”