Thickening of the lining of the uterus, called endometrial hyperplasia, may lead to cancer, but is not always a sign of cancer, according to the American Congress of Obstetricians and Gynecologists. Endometrial hyperplasia occurs when there is an excess of the hormone estrogen compared to the hormone progesterone.
Endometrial hyperplasia may develop when ovulation does not occur, therefore preventing the body from releasing progesterone, according to the American Congress of Obstetricians and Gynecologists. The lining of the uterus then swells because of the excess estrogen, which may lead to uterine cancer in some cases.
Endometrial hyperplasia often occurs when women use estrogen-like medication or take high doses of estrogen after menopause. Women who are obese or have irregular menstrual cycles may also develop endometrial hyperplasia. Signs of the condition include bleeding after menopause, unusually heavy bleeding during periods and menstrual cycles under 21 days. Endometrial hyperplasia is more likely to occur in white women who are over 35 years of age and have a family history of uterine, colon or ovarian cancer, according to the American Congress of Obstetricians and Gynecologists.
To prevent the condition, the American Congress of Obstetricians and Gynecologists suggests taking progesterone or progestin along with estrogen, losing weight if obese and regulating irregular menstrual periods with oral contraceptives.