Uterine cancer, or cancer of the uterus (womb), also may be called endometrial cancer. It is the:
- Fourth most common cancer in women
- Most common cancer of women’s reproductive organs
Each year, more than 40,000 women in the United States are diagnosed with uterine cancer. The average age for diagnosis of uterine cancer is 60. However, the number of younger women with uterine cancer is going up. Of uterine cancers, about:
- 25% are found before women go through menopause
- 5% are found before women are 40 years old
Early Diagnosis is Key
Most uterine cancers develop over a period of years. They may start as less serious problems such as endometrial hyperplasia, which is an overgrowth of cells in the lining of the uterus.
Fortunately, many uterine cancers are found early because of warning signs such as abnormal or postmenopausal bleeding. If uterine cancer is found in the earliest stages, it often can be treated successfully.
Uterus Plays a Part in Reproduction
The uterus is where a fetus grows when a woman is pregnant. It is hollow and pear shaped with two main parts:
- The cervix, which is the bottom part and extends into the vagina (the birth canal)
- The body of the uterus is the upper part. It also may be called the corpus. It has two main parts -- the muscle wall, which contracts when a woman has a baby, and the inner lining (endometrium).
When a woman menstruates (has a period), the endometrium becomes thicker. If she does not become pregnant, the new endometrial tissue goes out of the body as menstrual flow (blood). This happens about every month until a woman stops having periods. When a woman stops having periods it is called menopause.
Uterine Cancer Types
There are three types of uterine cancer.
Endometrial cancer: Almost all uterine cancers start in the lining of the uterus (endometrium). The two main types of endometrial cancer are:
- Endometroid adenocarcinoma: This accounts for most cases of endometrium cancer.
- Uterine carcinosarcoma: The cancer cells look like endometrium cancer and sarcoma.
Uterine sarcomas: These are less common types of uterine cancer and start in the muscle wall of the uterus.
Uterine Cancer Risk Factors
Anything that increases your chance of getting uterine cancer is a risk factor. These include:
- Obesity: Being overweight raises your risk two to four times. A higher level of fat tissue increases your level of estrogen.
- Eating a diet high in fat
- Age: More than 95% of uterine cancers occur in women 40 and older.
- Tamoxifen: This breast cancer drug can cause the uterine lining to grow. If you take Tamoxifen and have changes in your menstrual period or bleeding after menopause, it is important to let your doctor know.
- Estrogen replacement therapy (ERT) without progesterone if you have a uterus. Birth control pills may lower your risk.
- Personal/family history of uterine, ovarian or colon cancer. This may be a sign of Lynch syndrome (hereditary non-polyposis colorectal cancer or HNPCC). Learn more about hereditary cancer syndromes.
- Ovarian diseases, such as polycystic ovarian syndrome (PCOS)
- Complex atypical endometrial hyperplasia: This precancerous condition may become uterine cancer if not treated. Simple hyperplasia rarely becomes cancer.
- Never having been pregnant
- Number of menstrual cycles (periods): If you started having periods before 12 years old or went through menopause late, your risk of uterine cancer may be higher.
- Breast or ovarian cancer
- Pelvic radiation to treat other kinds of cancer. The main risk factor for uterine sarcoma is a history of high-dose radiation therapy in the pelvic area.
Not everyone with risk factors gets uterine cancer. However, if you have risk factors, it’s a good idea to discuss them with your doctor.
Behavioral and lifestyle changes can help prevent uterine cancer. Visit our prevention and screening section to learn how to manage your risk.
Some cases of uterine cancer can be passed down from one generation to the next. Genetic counseling may be right for you. Learn more about the risk to you and your family on our genetic testing page.