Tests for Endometrial Cancer

If your regular health care provider believes there’s a possibility you could have endometrial cancer, you should be examined by a gynecologist (a doctor trained to diagnose and treat diseases of the female reproductive system). Gynecologists can diagnose endometrial cancer and sometimes treat it. Specialists who treat cancers of the endometrium and other female reproductive organs are called gynecologic oncologists.

Medical history and physical exam

If you have any of the 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 examine you and give you a pelvic exam feeling the uterus, vagina, ovaries, and rectum to check for any unusual findings. A , Pap test, often done with a pelvic examination, is primarily used to screen for cervical cancer. Sometimes, the Pap test may find abnormal glandular cells, which are caused by endometrial cancer.

Using ultrasound to diagnose endometrial cancer

Ultrasound is often one of the first tests used to look at the uterus, ovaries, and fallopian tubes in those 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 if you are having a pelvic ultrasound you will be asked to drink lots of water before the test.

A transvaginal ultrasound (TVUS) is often a better method of looking 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). During the TVUS, salt water (saline) may be put into the uterus to help the doctor see the uterine lining more clearly. This technique is called saline infusion sonohysterography.     

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 used diagnostic test for endometrial cancer and is very accurate for those who have gone through menopause. 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.

Using hysteroscopy to diagnose endometrial cancer

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 anything abnormal, such as cancer or a polyp. This procedure may be done in the office using local anesthesia (numbing medicine) while the patient is awake.

Dilation and curettage (D&C) for endometrial cancer

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. This procedure uses instruments to enlarge (dilate) the cervical canal in order to access the uterus. Another instrument is then used to scrape (curettage) tissue from inside the uterus. This may be done with or without a hysteroscopy.

A D&C is a short outpatient procedure. It can be done while you are under a level of anesthesia determined by your health care team, based on factors such as your health and your preferences.               

Tests on 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 usually include a description of the type of cancer and the grade of the cancer. The report may also include the results of the initial screening test for Lynch syndrome  and additional molecular classifications.         

For more information about the classification of endometrial cancer, see What Is Endometrial Cancer?    

Testing endometrial tissue samples for gene changes    

Tumor cells can be tested for protein and gene changes that will identify those at increased risk for having Lynch syndrome and will identify molecular characteristics of the tumor that will guide treatment. These 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 Lynch syndrome is faulty

If these protein or DNA changes are present, a doctor may recommend  genetic testing for the genes that cause Lynch syndrome.   

The cancer cells might also be tested to see if treatment with immunotherapy might be an option, especially for more advanced endometrial cancers.

Tests to look for endometrial 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

You might have an x-ray of your chest 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. 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 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 injected via 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 patient 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 more in the past, but now are rarely part of the work up for endometrial cancer.

Blood tests used in endometrial cancer

Complete blood count

The complete blood count (CBC) measures 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. This test however is not used to diagnose endometrial cancer. Some doctors use CA-125 to help understand if the treatment is working. For example, the level of CA 125 may be high before surgery or any other treatment and might decrease after the treatment.