On Jan. 8, Surgeon General David Satcher said much the same thing about the federal government's action on obesity. Citing the National Center for Health Statistics estimate that 60 percent of Americans over the age of 20 are overweight or clinically obese, Satcher announced a preliminary plan to form a national strategy on the problem. It will help identify obesity as a significant contributor to a serious health condition. The connection with cancer has been established for some time but it hasn't gotten a lot of attention. Obesity can increase the risk of breast cancer because fat cells convert estrogen to estradiol, a more active form of the hormone that can promote the growth of tumors, Thun says.
Body shape affects the risk of other cancers.
Being shaped like an apple interferes with cells' uptake of glucose after meals, causing oversecretion of insulin. There is increased production of insulin-like growth factor, which is related to the growth factors that promote cancer of the colon, breast and prostate. In its prediction of cancer incidence, the ACS says there will be 1.268 million cases in the United States this year, up from 1.220 million in 2000. The overall increase is predicted because the overall population has increased as has the aged population, since the risk of cancer rises with age. Age-adjusted incidence and mortality rates are falling, because of screening tests that detect cancer at earlier, treatable stages, because of advancements in treatment and because fewer Americans are smoking.