Obesity and Cancer

The results of a recent study add to the significant body of existing evidence linking overweight and obesity to increased health risks. A recent study confirmed the association between being overweight and cancer. Among postmenopausal women in the UK, 5% of all cancers (about 6000 annually) are attributable to being overweight or obese. For endometrial cancer and adenocarcinoma of the oesophagus, body mass index represents a major modifiable risk factor; about half of all cases in postmenopausal women are attributable to overweight or obesity." In a prospective cohort study involving data from 1.2 million women between the ages of 50 and 64 years (UK women participants in the Million Women Study), increasing body mass index (BMI) was associated with a significant increase in the risk of cancer. Subjects were followed up for an average of 5.4 years for cancer incidence and 7.0 years for cancer mortality, during which time 45,037 incidences of cancer were reported and 17,203 deaths from cancer occurred. Increasing BMI was associated with increased risk of the following cancers: endometrial cancer, adenocarcinoma of the esophagus (2.38), kidney cancer (1.53), leukemia (1.50), multiple myeloma (1.31), pancreatic cancer (1.24), non-Hodgkin's lymphoma (1.17), ovarian cancer (1.14), breast cancer in post-menopausal women (1.40), colorectal cancer in pre-menopausal women (1.61), and all cancers combined (1.12). Similar associations were found between BMI and risk of mortality from cancer.

"Cancer incidence and mortality in relation to body mass index in the Million Women Study: cohort study," Reeves GK, Pirie K, et al, BMJ, 2007; 335(7630): 1134. (Address: Cancer Epidemiology Unit, University of Oxford, Oxford OX3 7LF.