Obesity Associated with Higher Cancer Risk among Veterans
In a study of 4.5 million patients hospitalized at Veterans Affairs hospitals over a 27-year time period, researchers found an increased risk for nearly 20 different cancers in those men who were obese. The study appears in the January/February issue of Cancer Causes and Control. Claudine Samanic and co-workers, all from the National Cancer Institute's (NCI's) Division of Cancer Epidemiology and Genetics, examined medical histories from computerized discharge notes from Veterans Affairs hospitals across the country. They assessed records for over 3.6 million white men and over 800,000 black men. Among obese veterans, they found an increased risk for cancers of the colon and kidney, which have been reported in numerous other studies, but also an increased risk for a number of less common cancers, such as male breast, lower esophagus, gallbladder, thyroid, extrahepatic bile duct, and connective tissue cancers, as well as malignant melanoma, multiple myeloma, chronic lymphocytic leukemia, and acute myeloid leukemia. Read more
The Complex Interaction of Diet, Physical Activity, and Genetics in Cancer Prevention and Control
At a time when nearly two-thirds of the U.S. population is considered overweight or obese, compelling evidence suggests that excess body weight is a risk factor for many cancers. However, in terms of weight-related factors, body weight alone does not completely determine an individual's ability to prevent or survive cancer. Instead, cancer researchers use the term "energy balance" to describe the complex interaction among diet, physical activity, and genetics on growth and body weight over an individual's lifetime and how those factors may influence cancer risk.
NCI has supported epidemiologic research in large cohort and case-control studies looking at the effects of weight, diet, physical activity, and cancer outcomes. These and other studies suggest that being overweight or obese increases the risk for postmenopausal breast cancer, colon cancer, adenocarcinoma of the esophagus, endometrial cancer, renal cell carcinoma, and several other cancers. Other studies, including some basic animal and cell culture studies, have explored the mechanisms by which obesity may influence cancer risk. Clinical intervention studies involving small groups of patients have placed people on specific diet, activity, and weight-control regimens to see how those factors influence cancer risk. This research is promising and should yield great insights into how these particular behavioral and genetic factors contribute to the cancer burden. Read more