Excess body fat is associated with many different cancers

Studies have already reported a clear link between increased body fat and cancer. To fine tune these associations by sex and cancer type, researchers reviewed and reanalysed international data from 76 prospective studies reporting nearly 300 000 incident cases⇑ ⇑. Increased body mass index (BMI) was most strongly associated with adenocarcinoma of the oesophagus (risk ratio per 5 kg/m² increase 1.52 in men; 1.51 in women) and renal cancer (1.24 in men; 1.34 in women) in both sexes, thyroid and colon cancers in men, and endometrial and gall bladder cancers in women. The researchers found weaker but still significant associations between BMI and many other cancers, including postmenopausal breast cancer in women and rectal cancer and malignant melanoma in men.

The findings were generally consistent in different populations, except for an unusually powerful association between increased BMI and breast cancer in the Asia-Pacific area, which the authors say deserves a closer look.

The nature of the association between excess body fat and cancer is unknown. But the increasing prevalence of obesity in most developed countries will probably be accompanied by a similar increase in cancers and cancer deaths, say the researchers. National cancer plans should include urgent measures to help people eat less, exercise more, and lose weight for good.

US medical schools fail to manage institutional links with industry

Many academic institutions in the US have explicit policies governing financial links between industry and individual researchers and doctors. But they seem more reluctant to manage financial competing interests at the institutional level, according to a survey of medical schools. Only 30 of the 86 deans who responded said their medical school “had adopted a . . . policy covering financial interests held by the institution.” A further third said that they were …