Obesity is probably a factor in some of the almost 22,000 new diagnoses of ovarian cancer that will be handed out this year to American women, a new study says. The finding adds ovarian cancer, the deadliest of the gynecological malignancies, to a growing list of diseases linked to carrying far too much weight.
Research has found obesity to contribute to a person's risk for a wide range of illnesses, including cardiovascular disease, type 2 diabetes, and cancers of the breast, colon, pancreas and esophagus.
In the case of ovarian cancer, which affects 8 in 100,000 women in the United States, the role of obesity is small: about 5% of U.S. cases of this deadly cancer might be attributable, at least in part, to a woman's obesity, concluded the American Institute for Cancer Research and the World Cancer Research Fund, which released a report on ovarian cancer Tuesday.
If American women maintained a healthy weight - with body mass index lower than 30 - the report calculates that 1,112 cases of ovarian cancer might be prevented each year.
The report also concludes that a woman's tall stature puts her at higher risk of ovarian cancer. But it notes that tallness itself does not appear to confer that greater risk; rather, some of the factors that result in tallness may also contribute to tumor establishment and growth, the experts suggested. Taller people have been found to be at greater risk for a wide range of other cancers as well.
Ovarian cancer typically progresses with no recognizable symptoms, and as a result is often diagnosed in advanced stages, when it is harder to treat. Ovarian cancer claims the lives of about 14,000 women in the United States annually, a number that has scarcely budged in 40 years.
It is far more common in post-menopausal women - almost 70% of those diagnosed with ovarian cancer are older than 54. But the new study found that obese pre-menopausal women have a more elevated risk of ovarian cancer (compared with non-obese pre-menopausal women) than do obese post-menopausal women (compared with their non-obese peers).
The cancer specialists who drafted the report cited mounting evidence that obesity-induced disturbances both of the metabolism and of sex hormones probably explain the link between obesity and ovarian cancer. High levels of the hunger hormone leptin, and of circulating insulin - both more common in the obese - spur an increase in growth factors that promote tumors. And accumulated fat can be a powerful producer of estrogen, which can fuel some cancer growth.