The researchers -- at Vanderbilt University in Nashville, Tenn., and the Shanghai Cancer Institute in China -- studied 832 women with endometrial cancer and a control group free of the disease. They found the risk of endometrial cancer -- cancer of the cells lining the uterus -- was cut by as much as 30 percent by physical activity such as household chores and walking.

They presented their findings at the American Association for Cancer Research's annual meeting in Orlando.

Another study showed the chances of surviving breast cancer were also improved by taking exercise. Women who performed more than four hours of chores a day experienced more cancer protection than for those who did less than two hours' housework.

Women who walk for 60 minutes a day seem to receive more protection than those who walked less than 30 minutes a day.

A separate study, by researchers from Brigham and Women's Hospital and Harvard University in Boston, found the risk of death for women who had breast cancer was up to 54 percent less for women who exercised.