Endometrial Cancer Risk Factors

A risk factor is anything that raises your chance of getting a disease such as cancer. Different cancers have different risk factors. Some risk factors, like smoking or sun exposure, can be changed. Others, like a person’s age or family history, can’t be changed.

Although certain factors can increase the risk for developing endometrial cancer, they don't always cause the disease. Many who have risk factors never develop endometrial cancer.

Some with endometrial cancer don't have any known risk factors. Even if someone with endometrial cancer has one or more risk factors, there is no way to know which, if any, of them caused the cancer.

Factors that increase the risk for endometrial cancer

Estrogen-only hormone replacement therapy

Estrogen-replacement therapy is given to improve symptoms of menopause. No progestin (another hormone) is given. This is called unopposed estrogen therapy. This can be given in the form of a pill, patch, or vaginal ring. It is a risk factor when the person taking it still has a uterus. For more information about the cancer risks linked to hormone treatment after menopause, see Menopausal Hormone Therapy and Cancer Risk.

Tamoxifen

Tamoxifen is a drug that is used to help prevent and treat breast cancer. Tamoxifen acts as an anti-estrogen in breast tissue, but it acts like an estrogen in the uterus. The risk of developing endometrial cancer from tamoxifen is very low (less than 1% per year). Because the risk is so low, the benefits of tamoxifen almost always outweigh the rare risk of endometrial cancer. If you have concerns about your uterine cancer risk and your breast cancer treatment plan includes tamoxifen, talk to your health care team.

Number of menstrual periods in a lifetime

Starting menstruation at a young age and going through menopause at a late age increases the exposure of the endometrium to estrogen and therefore increases the risk of endometrial cancer.

No pregnancies

The risk of endometrial cancer is higher if you have never been pregnant compared to having at least one pregnancy.

Certain medical conditions

Having a medical condition such as polycystic ovary syndrome (PCOS) and estrogen-secreting ovarian tumors increases the risk of uterine cancer.

Obesity

The ovaries produce the most estrogen before menopause. But fat tissue can change a hormone called androgen into estrogen. Having more fat tissue can increase estrogen levels, especially after menopause, which increases the risk of endometrial cancer.

Metabolic syndrome

Metabolic syndrome is a combination of medical conditions that typically includes obesity, diabetes, and hypertension. These conditions are linked to an increased risk of endometrial cancer.

Diet

A high-fat diet can increase the risk of many cancers, including endometrial cancer. Because fatty foods are also high-calorie foods, a high-fat diet can lead to obesity, which is a well-known endometrial cancer risk factor.  To learn more, read the American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention.

Endometrial hyperplasia

Endometrial hyperplasia is an increased growth of the endometrium. If the hyperplasia is called atypical, it has a higher chance of becoming a cancer.

Age

The risk of endometrial cancer increases with age and most commonly occurs after menopause.          

Genetic conditions

Lynch syndrome or hereditary non-polyposis colon cancer (HNPCC) and Cowden syndrome are genetic conditions that increase the risk of endometrial cancer. More information about inherited cancer syndromes can be found in Family Cancer Syndromes.

First-degree relative ( parent, sibling, or child) with endometrial cancer

Some families have a higher rate of only endometrial cancer. These families may have a different genetic disorder that hasn't been found yet. 

Race

Black people have a higher chance of being diagnosed with advanced endometrial cancer. Black people and Hispanic people also have a higher risk of developing more aggressive tumors.

Chemical exposure (hair relaxers)

Some studies have found that using chemical hair straighteners (relaxers) often and for many years might increase the risk of endometrial cancer. However, scientists aren’t sure which chemical in the straighteners might be causing this risk. Further studies have found that the increased risk for endometrial cancer was particularly high in Black women who are post-menopausal.

Radiation therapy

Previous radiation therapy for another cancer in the pelvic area, which is the lower part of the abdomen between the hip bones, increases the risk of endometrial cancer.

Factors that lower the risk for endometrial cancer

Oral contraceptive pills

Oral contraceptives pills (OCP) including both estrogen-progestin contraceptives as well as progestin-only contraceptives. The risk is lowest when they are taken long-term, and this protection lasts for at least 10 years after the pills are stopped.

Intrauterine contraceptive devices (IUDs)

Both progesterone-containing IUDs and copper IUDs decrease the risk of endometrial cancer.

Hormone replacement therapy

If you use hormone therapy after menopause, use of a medication that contains both estrogen and progesterone will help reduce risk.

Pregnancy

During pregnancy, the level of progesterone is high, which protects against endometrial cancer. Multiple pregnancies decrease the risk even more. Breastfeeding also is associated with a decrease in a mother's uterine cancer risk. 

Exercise

An increase in physical activity can help maintain a healthy weight and lower your risk of endometrial cancer.