Where does endometrial cancer spread to?
Endometrial cancer arises from the lining of the uterus, called the endometrium. The diagnosis is made through a curette, which takes some tissue from the endometrium for analysis under the microscope.
Once diagnosed with endometrial cancer, it is important to determine if or how far the cancer has spread. To do that, investigations (e.g., medical imaging) and surgery will determine a cancer ‘stage’ for each patient. Typically, a numbered staging system is used. Most types of cancer have 4 stages, numbered from 1 to 4. You may also see roman numerals used. The lower the number, the less the cancer has spread.
Endometrial cancer typically grows from the endometrium (the inside of the uterus) into the surrounding muscle layer (the myometrium) towards the outer lining of the uterus. It can also grow into the adjacent fallopian tubes, which are attached to the uterus and from here to the ovaries. Endometrial cancer cells can also shed into the cervix and from here to the vagina.
All tissues contain lymphatic vessels that drain body fluids and channel the lymphatic fluid back to the heart. Sometimes, cancerous tissues shed cancer cells into those lymphatic vessels and transport them into draining lymph nodes that are located in the pelvis and the abdomen.
Finally, some rare cancer types can spread through the blood stream to cause metastases in lung, liver or other organs.
The International Federation of Gynecology and Obstetrics (FIGO) classifies endometrial cancer into four stages:
Stage 1 (I): Cancer is present only in the uterus.
Stage 1 is divided into two categories:
- 1A: The cancer is limited to the inner lining of the uterus (endometrium) or has spread less than halfway into the muscle layer (myometrium).
- 1B: The cancer has spread more than halfway through the myometrium.
Stage 2 (II): Cancer has grown into the cervix (but still hasn’t spread outside the uterus).
In stage 1 and 2 the most common symptoms are unusual vaginal bleeding, spotting, or discharge.
Stage 3 (III): Cancer has spread beyond the uterus/cervix to the vagina, ovaries, fallopian tubes, and/or lymph nodes in the pelvis or abdomen.
Stage 3 is subdivided into the following:
- Stage 3A: Cancer is in the outer layer of your uterus or the fallopian tubes and ovaries.
- Stage 3B: It has spread to the tissues around the uterus or vagina.
- Stage 3C1: The cancer has spread outside of the uterus and to the lymph nodes of the pelvis.
- Stage 3C2: Cancer cells are inside the body of the uterus and the lymph nodes of the higher aorta.
In Stage 3, in addition to unusual vaginal bleeding, you may experience discomfort or pain in the abdomen, bloating, feeling full quickly, and difficulty or pain urinating.
Stage 4 (IV): Cancer has spread to the urinary bladder, rectum, or organs located far from the uterus, such as the lungs or bones, or to lymph nodes in the groin.
This is referred to as metastatic or advanced cancer and has two subcategories:
- Stage 4A: The cancer has spread to the inner lining of the bladder or rectum, and may or may not have spread to nearby lymph nodes.
- Stage 4B: The cancer has spread to the upper abdomen—the fat that supports your lower abdomen (the omentum)—or to distant organs away from the uterus such as your lungs, liver, and bones. It may have spread to the groin lymph nodes.
In Stage 4, the symptoms are similar to Stage 1-3, and you may also have shortness of breath or pain in areas where the cancer has spread. If you have any signs or symptoms of endometrial cancer, they are persistent and unusual, you should speak to your GP in the first instance.
Types of Endometrial Cancer
Type 1 endometrial cancers are typically slow growing and often detected before they spread to other parts of the body. Type 1 is the most common type of endometrial cancer diagnosed in Australian women.
Type 2 cancers are less common and include serous and clear cell type. These cancers are more aggressive and tend to grow faster, therefore are more likely to spread to other organs.
If you wish to read about treatment and outcomes of endometrial cancer, please refer to the Uterine Cancer page.