Your tumor grade measures how aggressive your cancer is and how likely it is to spread. Having a lower grade means your cancer is less likely to spread, whereas higher grades reflect more aggressive, fast-growing tumors.

In this article, we’ll discuss how doctors stage and grade endometrial cancer and how quickly tumors can grow. We’ll also cover what happens when endometrial cancer becomes metastatic. Fortunately, new treatments for endometrial cancer are available to help shrink tumors and slow their growth.

How Is Endometrial Cancer Staged and Graded?

Endometrial cancer staging and grading differ a bit from how they’re done for other cancer types. Most cancers use the American Joint Committee on Cancer (AJCC) TNM staging system. Doctors also use the International Federation of Gynecology and Obstetrics (FIGO) system for endometrial cancer. According to the American Cancer Society, these systems are very similar.

The AJCC and FIGO staging systems both use Roman numerals I, II, III, and IV (1, 2, 3, and 4) to describe the different stages. Stage 1 is least severe, and stage 4 is most severe. Staging considers three key factors:

• How large the tumor is and how far it’s spread
• Whether the tumor has spread to nearby lymph nodes (tiny immune system organs that filter your blood)
• Whether the cancer has metastasized (spread) to distant parts of the body

What Is Endometrial Cancer Grading?

Endometrial cancer tumors also receive a FIGO grade based on how the cancer cells look under a microscope. Pathologists (doctors who study tissues) take a close look at these cells and compare them to normal cells. Pathologists grade tumors on a scale of 1 to 3 for low- to high-grade cancers.

Low-grade endometrial cancer cells look more like normal cells. They’re less aggressive and aren’t likely to spread or grow quickly. High-grade cancers don’t look like normal cells. They lose features of normal cells and become undifferentiated. Cells from high-grade tumors grow fast and tend to spread more than low-grade tumors.

The inside lining of the uterus — known as the endometrium — normally forms glands. These glands help fertilized eggs implant for pregnancy. The FIGO grading system looks at how many cells in the tumor form solid tumor tissue rather than healthy glands.

The FIGO grade can be:

• 1 — The tumor tissue contains 5 percent or less of solid tumor growth.
• 2 — The tumor tissue contains 6 percent to 50 percent of solid tumor growth.
• 3 — More than 50 percent of the tumor tissue contains solid tumor growth.

Both your stage and grade of endometrial cancer affect your treatment plan. Your oncologist will use your results to recommend the best medications and procedures to shrink or remove your tumor.

How Quickly Does Endometrial Cancer Progress?

There’s not much research into how quickly endometrial cancers grow, but they tend to be slow-growing. According to MD Anderson Cancer Center at Cooper, these cancers can take several years to form.

Researchers do know that almost 70 percent of people with endometrial cancer are diagnosed with early-stage disease. This means most cases are caught early, and the cancer hasn’t spread outside the uterus. Earlier-stage cancer is easier to treat and has a better prognosis (outlook).

Another 20 percent of people are diagnosed with cancer that has moved into nearby lymph nodes and organs. The last 10 percent have endometrial cancer that’s spread to faraway parts of the body.

How Does Endometrial Cancer Become Metastatic?

Research shows that many factors play a role in when endometrial cancer becomes metastatic. We know that higher-grade tumors are more aggressive and likely to spread. One study found that people with grade 3 tumors were five times more likely to have cancer spread to the lymph nodes.

Endometrial cancers are divided into types 1 and 2 depending on their grade. Type 1 cancers are usually slow-growing, low-grade tumors. Type 2 cancers are more aggressive and grow faster. Examples include papillary serous carcinoma and clear cell carcinoma. These cancers are more likely to metastasize than type 1 tumors.

Common places that endometrial cancer spreads to include:

• Pelvic lymph nodes
• Nearby structures such as the fallopian tubes, ovaries, and cervix
• Lungs
• Liver
• Bones

How Do Doctors Determine Endometrial Cancer Grading?

Doctors diagnose endometrial cancer with biopsies and imaging tests. They can also determine the stage and grade from these results.

An endometrial biopsy is a quick test done in your doctor’s office. Your doctor inserts a long, thin tube through the cervix into your uterus. They use suction to take a small tissue sample to look at under a microscope. A pathologist can then grade your endometrial cancer.

If the biopsy didn’t work, a dilation and curettage (D&C) can help diagnose endometrial cancer. Your doctor will dilate your cervix and then gently scrape the inner lining of the uterus to get a sample for a pathologist to grade. During this procedure, which is usually done in an operating room, your doctor also can look into the uterus using a camera device called a hysteroscope.

Ultrasound is usually the first imaging test for diagnosing endometrial cancer. However, if your oncology team thinks your cancer has spread, they may order other tests to look at your entire body for metastases in other organs. These tests include:

• Magnetic resonance imaging (MRI)
• Computed tomography (CT) scans
• Positron emission tomography (PET)

Each test works differently to find cancer that’s spread to certain organs. For example, MRIs are useful for finding metastases to the brain and spinal cord. These tests can also evaluate how deep the tumor has grown into the uterine muscle.

How Do Endometrial Cancer Treatments Change by Stage?

As your endometrial cancer stage changes, so do your treatments. If possible, your doctor will recommend surgery first. This is the most common endometrial cancer treatment. A total hysterectomy bilateral salpingo-oophorectomy removes your uterus, ovaries, and fallopian tubes.

Your surgeon may also remove lymph nodes to check for any cancer spread. Early-stage endometrial cancer is also treated with radiation therapy and chemotherapy. These approaches help prevent your cancer from growing back later.

If you have stage 2 or 3 disease with a high-grade tumor, your endometrial cancer surgery may be more intense. Your surgeon will likely perform a total hysterectomy to remove your reproductive organs. They’ll also remove the omentum — the fatty tissue covering your abdominal organs. You may have chemotherapy or radiation therapy after surgery to keep your cancer from returning.

Since stage 4 endometrial cancer has spread throughout the body, it can be harder to treat. People who have cancer that has spread only to the abdomen may be treated with debulking surgery. This procedure removes any visible tumor tissue on or around the uterus.

Other systemic (body-wide) treatments may be recommended to slow the growth of cancer cells wherever they occur. These can include:

• Immunotherapy — Activates the immune system to fight cancer
• Hormone therapy — Blocks hormones that endometrial cancer cells use to grow
• Targeted therapy — Blocks mutations (variations) in cancer cells

Some high-grade tumors don’t respond well to hormone therapy. In this case, your doctor will recommend another treatment to slow tumor growth.

Talk With Others Who Understand

On MyEndometrialCancerCenter, the site for people with endometrial cancer and their loved ones, people come together to gain a new understanding of endometrial cancer and share their stories with others who understand life with endometrial cancer.

Have you been diagnosed with advanced endometrial cancer? Has it progressed since your cancer diagnosis? How quickly did this happen? Share your experiences in the comments below.