Uterine sarcoma

Facts

The uterus is pear shaped with the narrow end pointing down. This narrow lower end, which extends into the vagina, is the cervix. The wider upper part is the body of the uterus, or the uterine corpus.

There are three layers to the body of the uterus:

  • Endometrium, the inner lining
  • Myometrium, a thick layer of muscle
  • Serosa, the outer covering, or membrane

Connective tissue called stroma supports the other uterine tissues.

What is uterine sarcoma?

Most cancer in the uterus—more than 95 percent—starts in the endometrium. This is called endometrial cancer or endometrial carcinoma. (“Carcinoma” is the term for cancer that starts in one of the body’s linings or membranes.) We discuss endometrial cancer in its own section of the website.

In rare cases, cancer starts in another tissue of the uterus. Most of these cancers are uterine sarcoma. (“Sarcoma” is the term for cancer that starts not in a body lining but in one of the body’s other tissues, like muscle, bone, fat, or fibrous tissue.) Only about 3% of uterine cancers are uterine sarcoma. Other less common uterine cancers are uterine papillary serous carcinoma, clear cell carcinoma, and carcinosarcoma (also called malignant mixed mesodermal tumors or malignant mixed mullerian tumors).

Uterine sarcoma occurs when cells in the body of the uterus, usually in the muscle layer, begin to grow abnormally. These cells do not respond to regular cell growth, division, and death signals like they are supposed to. They also don’t organize normally. Instead they grow into a tumor, which may break through into other layers of the uterus.

Although the cervix is part of the uterus, cancer that starts in the cervix is referred to as cervical cancer, and it’s discussed in its own section of this website.

This rest of this section is about uterine sarcoma.

Types

About 1,400 new cases of uterine sarcoma are diagnosed each year in this country. The three types of uterine sarcoma are: 

  • Uterine leiomyosarcoma, the most common type, which starts in the myometrium
  • Endometrial stromal sarcoma, a rare type, which starts in the connective tissue that supports the endometrium (endometrial stroma)
  • Undifferentiated sarcoma, a rare type, which is similar to endometrial stromal sarcoma but more aggressive, meaning it grows and spreads more quickly

Risk factors

These factors increase your risk for uterine sarcoma.

  • Having had radiation therapy to your pelvic area before. Radiation therapy can damage the DNA in cells in ways that can lead to cancer later. Some women who have had pelvic radiation develop uterine sarcoma years or decades after receiving this treatment.

  • Being African American. African-American women are about twice as likely to get uterine sarcoma as are women of European or Asian descent. Doctors do not yet know why the risk is different between these groups of women.

  • Being older. Risk for uterine sarcoma goes up as you age.

Radiation therapy The use of high-energy radiation from X-rays, gamma rays, neutrons, protons and other sources to kill cancer cells and shrink tumors. The use of high-energy radiation from x-rays, gamma rays, neutrons, protons and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy or brachytherapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body.

Signs and symptoms

A possible symptom of uterine sarcoma is abnormal vaginal bleeding, such as bleeding or spotting between periods or after menopause. This symptom is more common with endometrial stromal sarcoma and undifferentiated sarcoma of the uterus than with uterine leiomyosarcoma. Some women have other abnormal vaginal discharge that doesn’t appear to have blood in it.

The following may be signs or symptoms of uterine sarcoma, but they are uncommon:

  • Pain in the pelvic area

  • A mass or a sense of fullness in the pelvic area or abdomen

  • Frequent urination

  • Pain when urinating or having a bowel movement

  • Pain during intercourse

Conditions other than cancer may cause these signs and symptoms. If you have any of these, see your doctor to find out the reason.

Sign In medicine, a sign is something found during a physical exam or from a laboratory test that shows that a person may have a condition or disease. In medicine, a sign is something found during a physical exam or from a laboratory test that shows that a person may have a condition or disease. Some examples of signs are fever, swelling, skin rash, high blood pressure and high blood glucose. Sign In medicine, a sign is something found during a physical exam or from a laboratory test that shows that a person may have a condition or disease. In medicine, a sign is something found during a physical exam or from a laboratory test that shows that a person may have a condition or disease. Some examples of signs are fever, swelling, skin rash, high blood pressure and high blood glucose. Symptom A physical or mental problem that a person experiences that may indicate a disease or condition. Symptoms cannot be seen and do not show up on medical tests. A physical or mental problem that a person experiences that may indicate a disease or condition. Symptoms cannot be seen and do not show up on medical tests. Some examples of symptoms are headache, fatigue, nausea and pain. Symptom A physical or mental problem that a person experiences that may indicate a disease or condition. Symptoms cannot be seen and do not show up on medical tests. A physical or mental problem that a person experiences that may indicate a disease or condition. Symptoms cannot be seen and do not show up on medical tests. Some examples of symptoms are headache, fatigue, nausea and pain.

Diagnosis

If you have signs or symptoms that could be from uterine sarcoma (or another problem with your reproductive organs), your doctor will probably start by doing a general physical exam and then a pelvic exam.

To diagnose uterine sarcoma, doctors have to remove a small sample of tissue from your uterus and look at the cells under a microscope. Seattle Cancer Care Alliance has a dedicated pathologist who specializes in the diagnosis of gynecologic cancers.

Endometrial biopsy

As part of your work-up, your doctor may do an endometrial biopsy. The doctor inserts a thin, flexible, straw-like tube into your uterus through your cervix and scrapes or suctions out a small amount of endometrium so a pathologist can examine the cells for cancer.

Dilation and curettage

Dilation and curettage (D&C) is another way your doctor can get a sample of cells from inside your uterus. A narrow instrument called a dilator is inserted into your cervix to open it. Next the doctor uses a spoon-like tool called a curette to scrape some tissue from inside your uterus for examination.

Imaging studies

The only way to tell whether you have uterine sarcoma is to examine samples of tissue. In certain situations, your doctor may also want you to have imaging studies to get more information, such as whether your cancer has spread. These might include an X-ray, ultrasound, computed tomography (CT) scan, and magnetic resonance imaging (MRI) scan. 

Biopsy The removal of a sample of tissue or fluid that is examined to see whether cancer is present. This may be done with a large needle or through surgical removal of tissue or fluids. Computed tomography A procedure that uses a computer linked to an X-ray machine to make a series of detailed pictures of areas inside the body. The pictures are used to create three-dimensional (3-D) views of tissues and organs. A procedure that uses a computer linked to an X-ray machine to make a series of detailed pictures of areas inside the body. The pictures are taken from different angles and are used to create three-dimensional (3-D) views of tissues and organs. A dye may be injected into a vein or swallowed to help the tissues and organs show up more clearly. This scan may be used to help diagnose disease, plan treatment or find out how well treatment is working. Imaging In medicine, a process that makes pictures of areas inside the body. Imaging uses methods such as X-rays (high-energy radiation), ultrasound (high-energy sound waves) and radio waves. Magnetic resonance imaging A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. MRI makes better images of organs and soft tissue than other scanning techniques, such as computed tomography (CT) or X-ray. MRI is especially useful for imaging the brain, the spine, the soft tissue of joints and the inside of bones. Pathologist A physician who has special training in identifying diseases by studying cells and tissues under a microscope. Sign In medicine, a sign is something found during a physical exam or from a laboratory test that shows that a person may have a condition or disease. In medicine, a sign is something found during a physical exam or from a laboratory test that shows that a person may have a condition or disease. Some examples of signs are fever, swelling, skin rash, high blood pressure and high blood glucose. Symptom A physical or mental problem that a person experiences that may indicate a disease or condition. Symptoms cannot be seen and do not show up on medical tests. A physical or mental problem that a person experiences that may indicate a disease or condition. Symptoms cannot be seen and do not show up on medical tests. Some examples of symptoms are headache, fatigue, nausea and pain. Ultrasound A procedure that uses high-energy sound waves to look at tissues and organs inside the body. The sound waves make echoes that form pictures of the tissues and organs on a computer screen. A procedure that uses high-energy sound waves to look at tissues and organs inside the body. The sound waves make echoes that form pictures of the tissues and organs on a computer screen (sonogram). Ultrasound may be used to help diagnose diseases, such as cancer. It may also be used during pregnancy to check the fetus (unborn baby) and during medical procedures, such as biopsies. Also called ultrasonography.

Stages

Once uterine sarcoma has been diagnosed, doctors perform tests to determine the stage of the cancer. Staging is the process of determining:

  • The grade of your cancer (how abnormal the cells look and how likely the cancer is to grow and spread)

  • Whether (and how deeply) it has invaded other tissues of your uterus

  • Whether it has spread outside your uterus

Doctors use a cancer’s stage as a key factor in making treatment recommendations and estimating a patient’s chance for recovery. For uterine sarcoma, staging is typically done at the time of surgery, which means you and your health care team will probably need to wait until after surgery to make some of your treatment decisions.

The most common staging system for gynecological cancers is the International Federation of Gynecology and Obstetrics (FIGO) 2010 system. This is the system that gynecologic oncologists at Seattle Cancer Care Alliance use.

  • Stage I: Cancer is only in the uterus. It has not spread to any lymph nodes or distant parts of the body.

  • Stage II: Cancer has spread beyond the uterus but not outside the pelvic area. It has not spread to any lymph nodes or distant parts of the body.

  • Stage III: Cancer has spread to the abdomen but not to any lymph nodes or distant parts of the body; or cancer has spread to lymph nodes near the uterus but not to the bladder, rectum, or distant parts of the body.

  • Stage IV: Cancer has spread to the bladder or rectum, lymph nodes outside the pelvis, or organs outside the pelvis, such as the lungs, liver, or bones.

Grade In cancer, a grade is a description of a tumor based on how abnormal the cancer cells and tissue look under a microscope and how quickly the cancer cells are likely to grow and spread. In cancer, a grade is a description of a tumor based on how abnormal the cancer cells and tissue look under a microscope and how quickly the cancer cells are likely to grow and spread. Low-grade cancer cells look more like normal cells and tend to grow and spread more slowly than high-grade cancer cells. Grading systems are different for each type of cancer. They are used to help plan treatment and determine prognosis. Also called histologic grade and tumor grade. Gynecologic oncologist A physician who has special training in diagnosing and treating cancers of the female reproductive organs. Stage The extent of a cancer in the body. Staging is usually based on the size of the tumor, whether lymph nodes contain cancer and whether the cancer has spread from the original site to other parts of the body. Staging Performing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from where it first formed to other parts of the body. Performing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from where it first formed to other parts of the body. It is important to know the stage of the disease in order to plan the best treatment.