Understanding Uterine Cancer

If you're reading this, chances are you're curious about uterine cancer, or maybe you or a loved one has recently been diagnosed. Here you'll learn the basics of uterine cancer, including statistics about the disease and certain factors that may put an individual at higher risk for developing cancer of the uterus.

What is uterine cancer?

Uterine cancer is cancer occurring in the uterus. While it may spread, uterine cancer always begins in the uterus, typically in the endometrium (the lining) of the uterus. Endometrial cancer is the most common type of gynecological cancer, according to the Centers for Disease Control and Prevention (CDC). Uterine sarcomas are a less common type of uterine cancer, occurring in the myometrium, the muscle wall in the uterus.

The terms "uterine cancer" and "endometrial cancer" are often used interchangeably.

"Endometrial cancer is essentially cancer of the uterus," said Kecia Gaither, M.D., board-certified in OB-GYN and maternal-fetal medicine and director of perinatal services/maternal-fetal medicine at NYC Health + Hospitals/Lincoln in the Bronx in New York City.

Uterine cancer is different from cervical cancer, which affects the cervix, a canal connecting the uterus and the vagina.

Uterine cancer by the numbers

The American Cancer Society estimates that in 2023, there will be 66,200 new cases of uterine cancer diagnosed and about 13,000 people are expected to die from the disease. These estimates include uterine sarcomas, which make up about 10 percent of cases.

According to information from the World Cancer Research Fund, uterine cancer is the sixth-most common cancer in women and the 15th-most common cancer overall.

The average age for women at the time of a uterine cancer diagnosis is 60 and it's more common in Black women. The National Cancer Institute reports that uterine cancer deaths make up 2.1 percent of total cancer deaths nationwide, and 3.4 percent of new cancer diagnoses. The five-year relative survival rate is 81.3 percent. About 3 percent of women receive a uterine cancer diagnosis in their lifetime.

Researchers aren't exactly sure about the cause of uterine cancer, much like all types of cancer. What is known is that cells in the uterus change and mutate, leading to cancer.

Who's at risk for uterine cancer?

"Older age [postmenopausal women], obesity, having a genetic mutation that puts you at a higher risk for certain types of cancers, taking estrogen therapy alone without progesterone, having endometrial hyperplasia [and] taking Tamoxifen [are risk factors]," said Leah Millheiser, M.D., an OB-GYN and expert in menopause and female sexual medicine, and the chief medical officer at Evernow, based in California.

Other risks mentioned by Gaither include:

• Family history of uterine, colon or ovarian cancer
• Being older than 50
• Using estrogen alone for hormone replacement therapy 
• Increased number of menstrual cycles (periods beginning before the age of 12 or late menopause)
• Nulliparity (having never given birth)
• History of endometrial hyperplasia
• Diabetes or a metabolic syndrome
• History of polycystic ovary syndrome (PCOS)
• Being a black woman
• History of hypothyroidism 
• History of breast or ovarian cancer
• History of pelvic radiation therapy
• Diet high in animal fat (this is a risk for all types of cancer)

Early signs of uterine cancer

As with all cancers, early detection of uterine cancer improves the chance of survival. Early signs to watch out for include abnormal uterine bleeding in premenopausal women or uterine bleeding after menopause, Millheiser said.

Another sign to watch for is rapidly expanding uterine size, which can normally be seen as enlargement of the lower abdomen. If the area below the belly button feels hard or looks distended, it's crucial to be checked by a physician.

There isn't a foolproof way to know if you're predisposed to gynecological cancers (unlike the BRCA gene mutation for breast cancer, for example), so it's important to maintain regular gynecologist visits and notify your doctor if you're having any abnormal bleeding, especially if you're postmenopausal. About 5 percent of uterine cancer cases are hereditary and it may also run in families where colon or ovarian cancer is present.

Early detection is key, so if you have a family history of uterine, ovarian or colon cancer, try to be vigilant about screenings. An annual Pap smear may not be sufficient for finding uterine cancer, so you'll need an endometrial biopsy or transvaginal ultrasound if you suspect you may have uterine cancer. Maintaining a healthy weight and exercising regularly can help reduce the risk of uterine cancer.