Exercise associated with 34% reduced risk for endometrial cancer

9th Annual AACR Frontiers in Cancer Prevention Research Conference

PHILADELPHIA – Women who exercise at least 150 minutes per week saw their risk for endometrial cancer fall by more than one-third compared with inactive women, according the results of a population-based, case-control study.

Hannah Arem, a doctoral student at Yale School of Public Health, New Haven, Conn., said risk was reduced for women who engaged in moderate-to-vigorous exercise, such as fast-paced walking or certain forms of yoga, regardless of BMI. Arem presented the results during the Ninth Annual AACR Frontiers in Cancer Prevention Research Conference.

She told HemOnc Today that women in the study experienced a dose response related to exercise.

“The greatest reduction in risk occurred in women who went from no exercise to some exercise,” Arem said. “As the women exercised more, the greater the decrease in risk became.”

Researchers recruited 668 women with endometrial cancer from the Rapid Case Ascertainment Shared Resource at the Yale Cancer Center and enrolled 665 age-matched controls using random digit dialing. Researchers then collected information on participants’ demographic features, environmental exposures and lifestyle factors. They then used unconditional logistic regression to examine the relationship between moderate- to vigorous-intensity sports and/or recreational physical activity and risk for endometrial cancer.

Compared with women who did not exercise, women who reported exercising 150 minutes per week had a 34% reduced risk (OR=0.66; 95% CI, 0.50-0.87).

Using a composite measure of physical activity consisting of activity level and BMI, researchers concluded that women who got 150 minutes of activity each week and weighed less than 25 kg/m² had a 73% lower risk for cancer (OR=0.27; 95% CI, 0.19-0.38). Inactive normal weight women had a 52% reduced risk (OR=0.45; 95% CI, 0.31-0.65). Active overweight women, those who weighed more than 25 kg/m², had a 38% lower risk of endometrial cancer (OR=0.62; 95% CI, 0.47-0.83).

Arem said the mechanism of action is still unclear, but researchers believe the decrease is related to certain sex hormones, insulin production and/or percentage of body fat.

“We know that two-thirds of the population in the US is overweight and nearly one-third are obese, and we know that this is a risk factor for endometrial cancer,” she said. “Therefore, since we’ve discovered that physical activity is significantly associated with endometrial cancer, we think this is an important public health message for women who at risk.”– by Jason Harris

For more information:

Arem H. #B70. Physical activity and BMI in a population-based case-control study of endometrial cancer risk. Presented at: the 9th Annual AACR Frontiers in Cancer Prevention Research Conference; Nov. 7-10, 2010; Philadelphia.

Even in women who are heavy and feel like it’s hopeless, this study shows that exercise by itself has a positive effect. We should encourage everybody to be more physically active, whether they’re heavy or not. Exercise is good even for people who are not heavy who do not think their risk can be lowered with exercise. But for women who are heavy and frustrated, and it’s not easy to lose weight, exercise has advantages over and above weight loss.

– Judy E. Garber, MD, MPH
President-elect of the AACR,
Director, Center for Cancer Genetics and Prevention, Dana-Farber Cancer Institute

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