Increased BMI Ups Cancer Risk

Increased body mass index (BMI) may be associated with several common cancer types, according to the results of a study involving more than 5 million patients in the United Kingdom.

The study, published online on August 14, 2014, in the Lancet, used primary care data to explore the relationship between BMI and the most common site-specific cancers.

Of the 5.24 million patients included in the study, 166,955 developed 1 of the 22 cancer types studied. Overall, BMI was associated with 17 cancer types, but the nature of the relationships varied significantly by type. The results indicated that each 5 kg/m2 increase in BMI was associated with an increased risk for leukemia and cancers of the uterus, gallbladder, kidney, cervix, and thyroid. In addition, BMI was positively associated with liver, colon, ovarian, and postmenopausal breast cancers, but these associations varied by underlying patient characteristics. The researchers also found inverse associations with prostate and premenopausal breast cancer risk.

“Assuming causality, 41% of uterine and 10% or more of gallbladder, kidney, liver, and colon cancers could be attributable to excess weight,” the study authors write. “We estimated that a 1 kg/m2 population-wide increase in BMI would result in 3790 additional annual UK patients developing one of the ten cancers positively associated with BMI.”