Types and grades of womb cancer

The most common type of womb cancer is endometrial cancer. Endometrial means that the cancer starts in the lining of the womb. This lining is called the endometrium.

Most womb cancers start in specific cells in the womb lining and are adenocarcinomas.

The grade of a cancer tells you how much the cancer cells look like normal cells. Cancer cells are divided into 3 grades.

Endometrial cancer

Most womb cancers start in specific cells in the womb lining, the endometrium. There are several types of endometrial cancer. Three of the more common types are:

Endometrioid is pronounced endo-mee-tree-oyd. Adeno means that the cancerous cells are in the glandular tissue of the womb lining. Carcinoma means the cancer has started in tissues lining or covering internal organs.

Most endometrial cancers are adenocarcinomas. There are several types of adenocarcinomas:

  • not otherwise specified
  • adenocarcinoma with squamous differentiation
  • secretory adenocarcinoma
  • ciliated carcinoma
  • villoglandular

These cancers are often diagnosed at an early stage and so are usually treated successfully.

This type is much less common than endometrioid cancers. It also develops from the lining of the womb. This is called a non endometrioid cancer. It is a type 2 endometrial cancer. 

Clear cell carcinoma of the womb lining is very rare. These cells are also in the lining of the womb and get their name from looking clear under a microscope. 

This is also called a non endometrioid cancer and is a type 2 endometrial cancer.

Other types of endometrial cancers include:

  • undifferentiated carcinoma

  • mixed carcinoma

  • carcinosarcoma - has features of both endometrial cancer and sarcoma when looked at under a microscope. This is different form sarcoma of the womb

  • mesonephric-like carcinoma

  • gastrointestinal mucinous carcinoma

Type 1 and type 2 endometrial cancer

Doctors sometimes divide endometrial cancers into 2 types.

Type 1 cancers are the most common type. They are usually endometrioid adenocarcinomas, and are linked to excess oestrogen in the body. They are generally slow growing and less likely to spread.

Type 2 cancers are not linked to excess oestrogen. They are generally faster growing and more likely to spread. They include uterine serous carcinomas and clear cell carcinomas. 

Sarcoma of the womb (uterine sarcoma)

Sarcoma of the womb is different from carcinosarcoma. Carcinosarcoma is when there is a combination of sarcoma and carcinoma cells under the microscope. They are often type 2 cancers and more aggressive. Carcinosarcomas are treated as carcinomas and not sarcomas.

Sarcoma of the womb develop from cells in the muscle layer of the womb, rather than the lining. They are a type of soft tissue sarcoma and are much less common than endometrial cancer. 

Soft tissue sarcomas are cancers of the supporting tissues of the body. There are many subtypes and they can develop from any type of soft tissue such as muscle or blood vessels. They tend to spread in the bloodstream to other parts of the body especially the lungs. The treatment you need for this type of womb cancer is not the same as other types of womb cancer.

Leiomyosarcoma is the most common sarcoma of the womb. It is a cancer of the muscle wall.

Because sarcomas are different and need different treatments, we have separate information about them.

Cancer of the neck of the womb (cervix)

Although the cervix is part of the womb, cervical cancer is very different from womb cancer. 

Grading of your cancer

Grading is a way of dividing cancer cells into groups depending on how much the cells look like normal cells. This gives your doctor an idea of how quickly or slowly the cancer might grow and whether it is likely to spread.

Grade 1

The cells look very like normal cells. They are also called low grade or well differentiated. They tend to be slow growing and are less likely to spread than higher grade cancer cells.

Grade 2

The cells look more abnormal and are more likely to spread. This grade is also called moderately differentiated or moderate grade.

Grade 3

The cells look very abnormal and not like normal cells. They tend to grow quickly and are more likely to spread. They are called poorly differentiated or high grade.

Risk groups for endometrial cancer

Type of womb cancer

When your doctor takes a sample of cells, a biopsy, it is sent to the laboratory. They also test the cancer they remove during surgery. A specialist doctor does various tests on the cells. This can help diagnose cancer and show which type of womb cancer it is.

Gene changes

Some womb cancers have changes in genes (mutations) that make the cancer grow and divide. Your doctor may test the cancer for changes in these genes to further classify your cancer. It also helps them decide on the best treatment for your type of womb cancer. This is also called molecular classification and includes the following groups:

  • MMRd
  • p53abn
  • POLE mutations
  • NSMP

Hormone receptors

They will also look for hormone receptors. The number of hormone receptors is linked to the effectiveness of hormone therapy.

Risk

When you have surgery, they look at the cancer to find out: 

  • how fast growing your cancer is, also called the grade
  • how far it has grown into the womb's muscle layer or the cervix
  • whether it has spread into any lymph or blood vessels, also called lymphovascular space invasion (LVSI)

This information might help to describe the risk of your womb cancer spreading or coming back after treatment. It will also help your doctor decide about the best treatment for you. The risk can be:

  • low
  • intermediate
  • high-intermediate
  • high 
  • advanced metastatic

More information

To decide about what treatment you need your doctor looks at your type, grade and stage of your cancer. 

  • British Gynaecological Cancer Society (BGCS) uterine cancer guidelines: recommendations for practice
    J Morrison and others
    European Journal of Obstetrics and Gynecology and Reproductive Biology, March 2022. Volume 270, Pages 50 to 89

  • Cancer: Principles and Practice of Oncology (12th edition)

    VT DeVita, TS Lawrence, SA Rosenberg

    Wolters Kluwer, 2023

  • Cancer of the corpus uteri (FIGO Cancer Report 2018)

    F Amant and others 

    International Journal of Gynaecology and Obstetrics, 2018. Volume 143, Supplement 2, Pages: 37 to 50

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. If you need additional references for this information please contact patientinformation@cancer.org.uk with details of the particular risk or cause you are interested in.

Last reviewed: 
19 Mar 2024
Next review due: 
19 Mar 2027

Related links