Endometrial cancer causes

Causes
Most women with endometrial cancer have a history of unopposed and increased levels of estrogen. One of estrogen's normal functions is to stimulate the buildup of the endometrial lining of the uterus. Excess estrogen activity, especially in the setting of insufficient progesterone, may produce endometrial hyperplasia, which can be a precursor for cancer.

Increased estrogen may be due to:
 * obesity (> 30 lb or 14 kg overweight)
 * exogenous (medication)

The incidence of endometrial cancer in women in the U.S. is 1 % to 2 %. The incidence peaks between the ages of 60 and 70 years, but 2 % to 5 % of cases may occur before the age of 40 years. Increased risk of developing endometrial cancer has been noted in women with increased levels of natural estrogen.

Associated conditions include the following:
 * obesity
 * hypertension
 * polycystic ovary syndrome

Increased risk is also associated with the following:
 * nulliparity (never having carried a pregnancy)
 * infertility (inability to become pregnant)
 * early menarche (onset of menstruation)
 * late menopause (cessation of menstruation)

Women who have a history of endometrial polyps or other benign growths of the uterine lining, postmenopausal women who use estrogen-replacement therapy (specifically if not given in conjunction with periodic progestin) and those with diabetes are also at increased risk.

Tamoxifen, a drug used to treat breast cancer, can also increase the risk of developing endometrial cancer.

The same risk factors predisposes women to endometrial hyperplasia, which is a precursor lesion for endometrial carcinoma. An atypical complex hyperplasia carries a 30% risk of developing endometrial carcinoma, while a typical simple hyperplasia only carries a 2-3% risk.