Gynecologic Oncology Program

Endometrial Cancer

Risk Factors

Although the exact causes of endometrial cancer are not known, we do know that prolonged exposure to the female hormone estrogen increases a woman’s risk of developing the disease.

Many of the risk factors for developing endometrial cancer are related to changes in women’s production of hormones.

Risk factors include the following:

Late menopause or early onset of periods: The endometrium is exposed to estrogen during a woman’s menstrual cycle, so women who start menstruating early or who stop menstruating late are exposed to more estrogen and thus have a greater risk of developing endometrial cancer.
Not being pregnant: Because women produce more progesterone and less estrogen during pregnancy, pregnancy actually reduces the risk of developing endometrial cancer. Conversely, not having become pregnant or completing a pregnancy is a risk factor for the disease.
Tamoxifen: Recent research suggests that taking the drug Tamoxifen, which lowers a woman’s risk for breast cancer, may slightly increase the risk of developing cancer of the endometrium. Women who take Tamoxifen should have yearly pelvic exams and report any abnormal bleeding to their doctors.
Estrogen replacement: Estrogen replacement therapy, an approach to treating some of the symptoms and effects of menopause, may increase a woman’s risk of developing endometrial cancer, if estrogen is given alone. However, this risk is reduced if both estrogens and progestens are replaced.
Obesity: Because fat tissues can convert some hormones into estrogens, being very overweight may increase a woman’s chances of developing endometrial cancer.
Age, race, and socioeconomic status: The average age at diagnosis of endometrial cancer is 60. White women are 70 percent more likely to develop endometrial cancer than are African American women. Women who are well-off are more likely to develop the disease than are poor women.
Personal and family history: Women who have had breast or ovarian cancer and women with a family history of endometrial cancer are more likely to get the disease.

This page was last updated on: March 3, 2008.