- Risk Factors
- Signs & Symptoms
Endometrial cancer is a disease in which malignant (cancer) cells form in the tissues of the endometrium.
The endometrium is the lining of the uterus, a hollow, muscular organ in a woman's pelvis. The uterus is where a fetus grows. In most nonpregnant women, the uterus is about 3 inches long. The lower, narrow end of the uterus is the cervix, which leads to the vagina.
Cancer of the endometrium is different from cancer of the muscle of the uterus, which is called sarcoma of the uterus. Refer to the PDQ summary on Uterine Sarcoma Treatment for more information.
Taking tamoxifen for breast cancer or taking estrogen alone (without progesterone) can affect the risk of developing endometrial cancer.
Endometrial cancer may develop in breast cancer patients who have been treated with tamoxifen. A patient taking this drug should have a pelvic exam every year and report any vaginal bleeding (other than menstrual bleeding) as soon as possible. Women taking estrogen (a hormone that can affect the growth of some cancers) alone have an increased risk of developing endometrial cancer. Taking estrogen in combination with progesterone (another hormone) does not increase a woman's risk of this cancer.
Possible signs of endometrial cancer include unusual vaginal discharge or pain in the pelvis.
These and other symptoms may be caused by endometrial cancer. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:
- Bleeding or discharge not related to menstruation (periods).
- Difficult or painful urination.
- Pain during sexual intercourse.
- Pain in the pelvic area.
Tests that examine the endometrium are used to detect (find) and diagnose endometrial cancer.
Because endometrial cancer begins inside the uterus, it does not usually show up in the results of a Pap test. For this reason, a sample of endometrial tissue must be removed and examined under a microscope to look for cancer cells. One of the following procedures may be used:
- Endometrial biopsy: The removal of tissue from the endometrium (inner lining of the uterus) by inserting a thin, flexible tube through the cervix and into the uterus. The tube is used to gently scrape a small amount of tissue from the endometrium and then remove the tissue samples. A pathologist views the tissue under a microscope to look for cancer cells.
- Dilatation and curettage: Surgery to remove samples of tissue or the inner lining of the uterus. The cervix is dilated and a curette (spoon-shaped instrument) is inserted into the uterus to remove tissue. Tissue samples may be taken and checked under a microscope for signs of disease. This procedure is also called a D&C.
Certain factors affect prognosis (chance of recovery) and treatment options.
The prognosis (chance of recovery) and treatment options depend on the following:
- The stage of the cancer (whether it is in the endometrium only, involves the whole uterus, or has spread to other places in the body).
- How the cancer cells look under a microscope.
- Whether the cancer cells are affected by progesterone.
Endometrial cancer is highly curable.
After endometrial cancer has been diagnosed, tests are done to find out if cancer cells have spread within the uterus or to other parts of the body.
The process used to find out whether the cancer has spread within the uterus or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. Certain tests and procedures are used in the staging process. A hysterectomy (an operation in which the uterus is removed) will usually be done to help find out how far the cancer has spread.
There are three ways that cancer spreads in the body.
The three ways that cancer spreads in the body are:
- Through tissue. Cancer invades the surrounding normal tissue.
- Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
- Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.
When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.
The following stages are used for endometrial cancer:
In stage I, cancer is found in the uterus only. Stage I is divided into stages IA, IB, and IC, based on how far the cancer has spread.
- Stage IA: Cancer is in the endometrium only.
- Stage IB: Cancer has spread into the inner half of the myometrium (muscle layer of the uterus).
- Stage IC: Cancer has spread into the outer half of the myometrium.
In stage II, cancer has spread from the uterus to the cervix, but has not spread outside the uterus. Stage II is divided into stages IIA and IIB, based on how far the cancer has spread into the cervix.
- Stage IIA: Cancer has spread to the glands where the cervix and uterus meet.
- Stage IIB: Cancer has spread into the connective tissue of the cervix.
In stage III, cancer has spread beyond the uterus and cervix, but has not spread beyond the pelvis. Stage III is divided into stages IIIA, IIIB, and IIIC, based on how far the cancer has spread within the pelvis.
Stage IIIA: Cancer has spread to one or more of the following:
- the outermost layer of the uterus; or
- tissue just beyond the uterus; or
- the peritoneum.
- Stage IIIB: Cancer has spread beyond the uterus and cervix, into the vagina.
- Stage IIIC: Cancer has spread to lymph nodes near the uterus.
In stage IV, cancer has spread beyond the pelvis. Stage IV is divided into stages IVA and IVB, based on how far the cancer has spread.
- Stage IVA: Cancer has spread to the bladder and/or bowel wall.
- Stage IVB: Cancer has spread to other parts of the body beyond the pelvis, including lymph nodes in the abdomen and/or groin.
Recurrent Endometrial Cancer
Recurrent endometrial cancer is cancer that has recurred (come back) after it has been treated. The cancer may come back in the pelvis, in lymph nodes in the abdomen, or in other parts of the body.