Obesity-driven endometrial cancer: is weight loss the answer?

Endometrial cancer is the fourth most common cancer affecting British women, behind breast, lung and colon cancer. Over the past 20 years, the incidence of endometrial cancer has risen by 40%, and deaths by 20%, despite improved overall survival rates. Currently more than 1900 British women die from endometrial cancer each year, compared with fewer than 1500 at the turn of the century. The aging population, uterinesparing treatments for menstrual dysfunction and tamoxifen treatment for breast cancer have all contributed to this rise, but escalating obesity rates appear to be the major culprit. Endometrial cancer ranks highest amongst all cancers in its association with obesity. Every 5 kg/m increase in body mass index (BMI) confers a 1.6-fold increased risk of endometrial cancer. At a BMI of 42, a woman has an almost ten-fold increased risk of endometrial cancer than women of normal weight.Rates of obesity in England and Wales have trebled over the last two decades, and they are still on the increase. Currently, two-thirds of British women are overweight and nearly one-quarter obese. In Europe, excess weight has been estimated to account for 60% of all new endometrial cancer cases per year. Indeed, in the ASTEC trial, a European study of more than 1400 women with earlystage endometrial cancer, 80% of women with type-1 endometrial cancer were overweight (BMI > 25) and 50% were obese (BMI > 30). Thus, although an average woman has a 3% lifetime risk of endometrial cancer, an obese woman has a risk of 9–10%, and for morbidly obese women the risk may be even higher.