Tests for Endometrial Cancer

Endometrial cancer is most often diagnosed after a woman goes to her doctor because she has symptoms.

If there’s a possibility you could have endometrial cancer, you should be examined by a gynecologist. This is a doctor trained to diagnose and treat diseases of the female reproductive system. Gynecologists can diagnose endometrial cancer, and sometimes treat it. Specialists in treating cancers of the endometrium and other female reproductive organs are called gynecologic oncologists. These doctors treat all stages of endometrial cancer.

Medical history and physical exam

If you have any of the symptoms of endometrial cancer (see Signs and Symptoms of Endometrial Cancer), you should see a doctor right away. The doctor will ask about your symptoms, risk factors, and medical history. The doctor will also do a physical exam and a pelvic exam.

Ultrasound

Ultrasound is often one of the first tests used to look at the uterus, ovaries, and fallopian tubes in women with possible gynecologic problems. Ultrasound uses sound waves to take pictures of the inside of the body. A small wand (called a transducer or probe) gives off sound waves and picks up the echoes as they bounce off the organs. A computer translates the echoes into pictures.

For a pelvic ultrasound, the transducer is moved over the skin of the lower part of the belly (abdomen). Often, to get good pictures of the uterus, ovaries, and fallopian tubes, the bladder needs be full. That's why women getting a pelvic ultrasound are asked to drink lots of water before the test.

A transvaginal ultrasound (TVUS) is often better to look at the uterus. For this test, the TVUS probe (that works the same way as the ultrasound transducer) is put into the vagina. Images from the TVUS can be used to see if the uterus contains a mass (tumor), or if the endometrium is thicker than usual, which can be a sign of endometrial cancer. It may also help see if cancer is growing into the muscle layer of the uterus (myometrium).

A small tube may be used to put salt water (saline) into the uterus before the ultrasound. This helps the doctor see the uterine lining more clearly. This procedure is called a saline infusion sonogram or hysterosonogram. (Sonogram is another term for ultrasound.)

Ultrasound can be used to see endometrial polyps (growths) , measure how thick the endometrium is, and can help doctors pinpoint the area they want to biopsy.

Endometrial tissue sampling

To find out exactly what kind of endometrial change is present, the doctor must take out some tissue so that it can be tested and looked at with a microscope. Endometrial tissue can be removed by endometrial biopsy or by dilation and curettage (D&C) with or without a hysteroscopy. A gynecologist usually does these procedures, which are described below.

Endometrial biopsy

An endometrial biopsy is the most commonly used test for endometrial cancer and is very accurate in postmenopausal women. It can be done in the doctor's office. A very thin, flexible tube is put into the uterus through the cervix. Then, using suction, a small amount of endometrium is removed through the tube. The suctioning takes about a minute or less. The discomfort is a lot like menstrual cramps and can be helped by taking a nonsteroidal anti-inflammatory drug (like ibuprofen) before the procedure. Sometimes a thin needle is used to inject numbing medicine (local anesthetic) into the cervix just before the procedure to help reduce the pain.

Hysteroscopy

For this procedure, the doctor puts a tiny telescope (about ¹/₆ inch in diameter) into the uterus through the cervix. To get a better view of the inside (lining) of the uterus, the uterus is filled with salt water (saline). This lets the doctor look for and biopsy anything abnormal, such as a cancer or a polyp. This is usually done using a local anesthesia (numbing medicine) while the patient is awake.

Dilation and curettage (D&C)

If the endometrial biopsy sample doesn't provide enough tissue, or if the biopsy suggests cancer but the results are unclear, a D&C must be done. In this outpatient procedure, the opening of the cervix is enlarged (dilated) and a special instrument is used to scrape tissue from inside the uterus. This may be done with or without a hysteroscopy.

This procedure takes about an hour and may require general anesthesia (where drugs are used to put you into a deep sleep) or conscious sedation (drugs are put into a vein to make you drowsy) either with local anesthesia injected into the cervix or a spinal (or epidural). A D&C is usually done in an outpatient surgery area of a clinic or hospital. Most women have little discomfort after this procedure.

Testing endometrial tissue samples

Endometrial tissue samples removed by biopsy or D&C are looked at with a microscope to see if cancer is present. If cancer is found, the lab report will state what type of endometrial cancer it is (like endometrioid or clear cell) and what grade it is.

Endometrial cancer is graded on a scale of 1 to 3 based on how much it looks like normal endometrium. (See What Is Endometrial Cancer?) Women with lower grade cancers are less likely to have cancer in other part of their body and are less likely to have the cancer come back after treatment (recur).

Testing for gene and protein changes in the cancer cells

If the doctor suspects hereditary non-polyposis colon cancer (HNPCC) as an underlying cause of the endometrial cancer, the tumor cells can be tested for protein and gene changes. Examples of HNPCC-related changes include:

• Having fewer mismatch repair (MMR) proteins
• Defects in mismatch repair genes (dMMR)
• DNA changes (high levels of microsatellite instability, or MSI-H) that can happen when one of the genes that causes HNPCC is faulty

If these protein or DNA changes are present, the doctor may suggest genetic testing for the genes that cause HNPCC.

Testing the cancer cells for dMMR, MSI-H, and/or a high tumor mutational burden (TMB-H) might also be done to see if treatment with immunotherapy might be an option, especially for more advanced endometrial cancers.

Tests to look for cancer spread

If the doctor suspects that your cancer is advanced, you'll probably have to have other tests to look for cancer spread.

Chest x-ray

A plain x-ray of your chest may be done to see if cancer has spread to your lungs.

Computed tomography (CT)

The CT scan is an x-ray procedure that creates detailed, cross-sectional images of the inside of your body. For a CT scan, you lie on a table while X-rays are done. Instead of taking one picture, like a standard x-ray, a CT scanner takes many pictures as the camera rotates around you. A computer then combines these pictures into an image of a slice of your body. The machine will take pictures of many slices of the part of your body that's being studied.

CT scans are not used to diagnose endometrial cancer. But they can help see if the cancer has spread to other organs and to see if it has come back after treatment.

Magnetic resonance imaging (MRI)

MRI scans use radio waves and strong magnets instead of x-rays. The energy from the radio waves is absorbed and then released in a pattern formed by the type of tissue and by certain diseases. A computer translates the pattern of radio waves given off by the tissues into a very detailed image of the inside of the body. This creates cross sectional slices of the body like a CT scanner and it also makes slices that are parallel with the length of your body.

MRI scans are very helpful for looking at the brain and spinal cord. Some doctors also think MRI is a good way to tell whether, and how far, the endometrial cancer has grown into the body of the uterus. MRI scans may also help find enlarged lymph nodes with a special technique that uses very tiny particles of iron oxide. These are given into a vein and settle into lymph nodes where they can be spotted by MRI.

Positron emission tomography (PET)

In this test radioactive glucose (sugar) is given to look for cancer cells. Because cancers use glucose (sugar) at a higher rate than normal tissues, the radioactivity will tend to collect in the cancer. A scanner can spot the radioactive deposits. This test can be helpful for spotting small collections of cancer cells. Special scanners combine a PET scan with a CT to more precisely locate areas of cancer spread. PET scans are not a routine part of the work-up of early endometrial cancer, but may be used for more advanced cases.

Cystoscopy and proctoscopy

If a woman has problems that suggest the cancer has spread to the bladder or rectum, the inside of these organs will probably be looked at through a lighted tube. In cystoscopy the tube is put into the bladder through the urethra. In proctoscopy the tube is put in the rectum. These exams allow the doctor to look for cancer. Small tissue samples can also be removed during these procedures for testing. They can be done using a local anesthetic but some patients may need general anesthesia. Your doctor will let you know what to expect before and after these tests. These procedures were used a lot in the past, but now are rarely part of the work up for endometrial cancer.

Blood tests

Complete blood count

The complete blood count (CBC) is a test that measures different cells in the blood, such as the red blood cells, the white blood cells, and the platelets. Endometrial cancer can cause bleeding, which can lead to low red blood cell counts (anemia).

CA-125 blood test

CA-125 is a substance released into the bloodstream by many, but not all, endometrial and ovarian cancers. If a woman has endometrial cancer, a very high blood CA-125 level suggests that the cancer has likely spread beyond the uterus. Some doctors check CA-125 levels before surgery or other treatment. If they're elevated, they can be checked again to see how well the treatment is working (levels will drop after surgery if all the cancer is removed).

CA-125 levels are not needed to diagnose endometrial cancer, so this test isn’t done on all patients.