The type of womb cancer you have depends on the type of cell the cancer started in. The grade gives doctors an idea of how fast growing the cancer is.
Knowing the type and grade of your cancer helps your doctor to decide what treatment you need.
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.
About 95 out of every 100 (95%) endometrial cancers are adenocarcinomas.
Adeno means that the cells that have become cancerous are the cells of glandular tissue. So for the most common type of womb cancer, the cancer is in the glands of the endometrium. Carcinoma means that the cancer has started in a surface or lining layer of cells (the epithelium).
There are 3 types of adenocarcinoma:
More than 3 out of 4 adenocarcinomas of the womb lining are this type. Endometrioid is pronounced endo-mee-tree-oyd. These cancers are often diagnosed at an early stage and so are usually treated successfully.
There are different subtypes of endometrioid cancer. Some types have squamous cells as well as glandular cells. Adenoacanthomas have a mix of cancerous glandular cells and non cancerous (benign) squamous cells. If both the glandular cells and squamous cells are cancerous, it is called adenosquamous carcinoma.
This type is much less common than endometrioid cancers. Only about 5 out of every 100 womb cancers (5%) are the uterine serous type. This is a more quickly growing type of cancer that is more likely to come back than other types, even if it is caught early.
Clear cell carcinoma of the womb lining is very rare. These days, only about 1 or 2 cases of womb cancer in every 100 (1 to 2%) are clear cell cancer.
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 include uterine serous carcinomas and clear cell carcinomas. These cancers are not linked to excess oestrogen. They are generally faster growing and more likely to spread.
Sarcoma of the womb (uterine sarcoma)
These are cancers that 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 they are different we have separate information about them and their treatments.
Carcinosarcoma of the womb (uterine carcinosarcoma)
Carcinosarcoma is a rare type of womb cancer. It has features of both endometrial cancer and sarcoma when looked at under a microscope.
Doctors class carcinosarcomas as a type of endometrial cancer as they have similar risk factors and behave in a similar way. They generally treat them as a type 2 endometrial cancer.
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.
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.
The cells look more abnormal and are more likely to spread. This grade is also called moderately differentiated or moderate grade.
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
Researchers are looking into new ways of deciding what treatment you need. They are trying to find out about gene changes (mutations) in womb cancer and seeing if this can help them to decide the best treatment for you.
Doctors will use the information about the gene changes to describe womb cancer as either:
- low risk
- high risk
These groups describe how likely it is that your cancer will spread further, or come back after treatment.
They hope this will help to improve screening for women at high risk. It will also help doctors decide about the best treatment for different types of womb cancer.