You may hear the terms “uterine cancer” and “endometrial cancer” used interchangeably. But uterine cancer is an umbrella term that includes two distinct cancer types — endometrial cancer and uterine sarcoma. When people talk about uterine cancer, they usually are referring to endometrial cancer, which is far more common than uterine sarcoma. Endometrial cancer, in turn, is a general term for five or more subtypes. Uterine carcinoma and the cancers known as endometrial cancer have some symptoms and treatment options in common, but others are unique to each. The various conditions also have different prognoses.
Types of Uterine Cancer
The uterus is an organ in the pelvis. The wall of the uterus is called the myometrium and is made of muscle. The inner lining of the uterus is glandular tissue called the endometrium. Cancers are named based on whether they originate in the myometrium or the endometrium.
- Endometrial cancers develop from the inner lining of the uterus, or the endometrium. They account for 95% of uterine cancers.
- Uterine sarcomas develop from the myometrium, the layer of muscle in the wall of the uterus, or from the connective tissue nearby. They are rare.
Endometrial Cancer Types
Endometrial cancer is also called endometrial carcinoma. Most endometrial cancers start from glandular cells in the endometrium. Two types of tumors can develop, depending on how the cells respond to hormones such as estrogen. They are:
- Type I, including endometrioid adenocarcinoma. These tumors may grow in response to high levels of estrogen. Unusual vaginal bleeding can be an early symptom that prompts a person to go to a doctor, so these cancers are often diagnosed at early stages.
- Type II, which is less common, includes serous adenocarcinoma, papillary serous adenocarcinoma, clear cell carcinoma, carcinosarcoma, and undifferentiated carcinomas. These tumors typically do not respond to hormone signaling, may be more aggressive, and are more likely to be diagnosed at late stages.
Uterine Sarcoma Types
Most uterine sarcomas arise in the muscle and in nearby connective tissue of the uterine wall. Different types of uterine sarcoma include:
- Uterine leiomyosarcomas (LMS), start in the myometrium, a layer of muscle. LMS is the most common uterine sarcoma type.
- Endometrial stromal sarcomas (ESS) develop from connective tissue of the endometrium called the stroma.
- Undifferentiated sarcomas start in either the myometrium or the endometrium.
- Adenosarcoma tumors contain both glandular (endometrium) cells and stromal (connective tissue) cells.
How common is endometrial cancer?
Endometrial cancer is the most common gynecologic cancer. About 66,200 new cases of all types of uterine cancer will be diagnosed this year in the United States, according to the American Cancer Society. Most of these new cases — about 90% or 60,000 — will be endometrial cancer. The average age at diagnosis for endometrial cancer is 60. It is rare among those younger than 45. It is more common in Black women than white women.
Uterine sarcomas account for less than 10% of new diagnoses each year, about 3,000 to 6,000 cases. Leiomyosarcoma and endometrial stromal sarcoma are the most common types of uterine sarcoma. However, these cancers are rare. They usually develop after age 40, and the average age at diagnosis is 60. Leiomyosarcomas — but not other uterine sarcomas — occur twice as often in Black women as in white women.
Uterine Cancer Symptoms
Uterine cancer symptoms may include:
- Vaginal bleeding or spotting after menopause
- Heavier periods than normal, or bleeding between periods, before menopause
- Vaginal discharge without blood
- Pelvic pain
- Pain when urinating
- Pain during intercourse
- Changes in bowel habits (diarrhea or constipation)
- Vaginal discharge with an odor
- Abdominal discomfort, like pain or a feeling of fullness
- Lump or mass in the pelvis or abdomen
Diagnosing Uterine Cancer
In order to diagnose uterine cancers, your gynecologist will ask about your symptoms and health history, and will perform a physical exam and a pelvic exam. Imaging tests can detect abnormalities that suggest cancer. A diagnosis of cancer can be confirmed only by examining cells collected through a biopsy or surgery. Talk with your doctor about which tests are most relevant for you.
Imaging studies that may be used
- Ultrasound imaging is used to provide a picture of the uterus, ovaries, and fallopian tubes. Ultrasounds can be done with a wand that is drawn across the skin of the belly, or with a wand that is inserted into the vagina (transvaginal ultrasound).
- Computed tomography (CT) imaging can detect whether cancer has spread to other parts of the body.
- Magnetic resonance imaging (MRI) of the abdomen or pelvic organs is another way to evaluate for cancer spread.
- Positron emission tomography (PET) imaging may be performed at the same time as CT scans to look for cancer spread.
- Chest X-rays may show whether cancer has spread to the lungs.
Tissue sampling that may be performed
- An endometrial biopsy to collect a sample of tissue from the endometrium. The doctor inserts speculum in the vagina, and then uses a thin tube inserted into the uterus to obtain a tissue sample.
- Dilation and curettage (D&C) may be done if the results from an endometrial biopsy are unclear or if an office biopsy is not feasible. This outpatient procedure is usually performed in a surgical center.
- Tissue testing in a lab can identify cancer cells and provide information about their type and the grade of disease.
- Surgery to remove the uterus and cervix (hysterectomy), and often the fallopian tubes and ovaries, is commonly recommended to diagnose and treat uterine cancers. In some cases, staging surgeries are performed. Staging is a way to evaluate for cancer spread by removing lymph nodes and evaluating other sites for evidence of tumors.
- Tissue from people diagnosed with endometrial cancer will be screened for possible Lynch syndrome, a hereditary condition that predisposes people to many cancer types. For some patients further genetic testing for Lynch syndrome is recommended.
Uterine Cancer Treatment
Surgery to remove the cancer is usually a component of treatment for both endometrial cancers and uterine sarcomas. Depending on the type of cancer and findings at surgery, some people may also receive additional treatments such as:
- Radiation therapy may reduce the risk of a pelvic recurrence in some cases. Radiation can be delivered from outside the body, with a machine like an X-ray machine, or by using an insert placed in the vagina. It can be given alone or in combination with chemotherapy. If a patient is unable to have surgery, or chooses not to, radiation and/or chemotherapy may be given instead.
- Chemotherapy is used to reduce the risk of cancer recurring after surgery and to treat any residual disease that may remain after surgery. In some cases, chemotherapy is given before surgery to shrink tumors so that surgery will be less risky. Chemotherapy drugs may be given by mouth or intravenously. Chemotherapy may also be given alone, if surgery is not performed, or with radiation, to reduce or prevent spread or alleviate symptoms.
- Hormone therapy for endometrial cancer may be used to preserve fertility, or to reduce the risk of cancer recurrence. It is also sometimes used in cases where surgery is not possible. Hormone therapy is often used as a component of treatment for the cancer type known as low-grade endometrial stromal sarcoma (ESS).
- Immunotherapy is used for some cases of recurrent or advanced disease, and boosts the ability of the body’s immune system to fight cancer. Recent data indicate that immune therapy should be used together with chemotherapy for patients with advanced stage endometrial cancer after surgery.
- Targeted drug therapies home in on specific features of cancer cells to selectively kill them.
Uterine Cancer Support
Receiving a gynecologic cancer diagnosis can be overwhelming, but OCRA is here to help patients and their families every step of the way. We offer several options for support, including:
- Staying Connected, OCRA’s virtual support series for gynecologic cancer patients, survivors and their families. These groups are themed around a variety of topics and facilitated by an oncology social worker.
- Woman to Woman, which connects you with a survivor volunteer for peer support
- Inspire Online Community, a safe environment for conversations and insight
- Clinical Trial Finder, where you can be connected to clinical trials specific to your diagnosis