Overview

Uterine cancer (also known as uterine adenocarcinoma and endometrial cancer) is the most common cancer of a woman’s reproductive system. The pear-shaped uterus is hollow and located in a woman's pelvis between her bladder and rectum. The uterus is also known as the womb, where a baby grows when a woman is pregnant. It has three sections: the cervix (the narrow, lower section), the corpus (the broad, middle section), and the fundus (the dome-shaped, top section). The wall (the inside of the uterus) has two layers of tissue: endometrium (an inner layer), and myometrium (the outer layer), which is muscle tissue.

Every month during a woman's childbearing years, the lining of the uterus grows and thickens in preparation for pregnancy. If the woman does not get pregnant, this thick, bloody lining passes out of her body through her vagina during menstruation. This process continues until menopause.

Uterine cancer begins when cells in the uterus begin to change, grow uncontrollably, and eventually form a tumor. A tumor can be benign (noncancerous) or malignant (cancerous). Noncancerous conditions of the uterus include fibroids (benign tumors in the muscle of the uterus), endometriosis (endometrial tissue on the outside of the uterus or other organs), and endometrial hyperplasia (an increased number of cells in the uterine lining).

There are two major types of uterine cancer:

Adenocarcinoma. This type of cancer makes up more than 95% of uterine cancers. It develops from cells in the lining of the uterus, the endometrium. This cancer is also commonly called endometrial cancer.

Sarcoma. This form of uterine cancer develops in the uterine muscle, the myometrium. Sarcoma accounts for about 2% to 4% of uterine cancers. For more information on this type of cancer, visit Cancer.Net’s Sarcoma section.

Other, less common types of uterine cancer include carcinosarcoma and endometrial stromal sarcoma. Carcinosarcoma starts in the endometrium and is similar to both endometrial cancer and sarcoma. Endometrial stromal sarcoma starts in the connective tissue of the endometrium. Treatment for these types of uterine cancer is similar to the treatment of endometrial cancer. For more information on cancer of the cervix, read the Cancer.Net Guide to Cervical Cancer.

Statistics

In 2009, an estimated 42,160 women in the United States will be diagnosed with uterine cancer. It is estimated that 7,780 deaths from this disease will occur this year. Uterine cancer is the fourth most common cancer and the eighth most common cause of cancer death for women in the United States. Although uterine cancer rates are higher among white women than black women, black women are nearly twice as likely to die from uterine cancer as white women.

The one-year relative survival rate (percentage of people who survive at least one year after the cancer is detected, excluding those who die from other diseases) for uterine cancer is 92%. The five-year relative survival rate for a woman with a local (without spread) uterine cancer at diagnosis is about 96%. If the cancer is diagnosed with regional spread, the five-year relative survival rate is about 68%, and if diagnosed after the cancer has spread more distantly, it is 24%.

Cancer survival statistics should be interpreted with caution. These estimates are based on data from thousands of cases of this type of cancer in the United States each year, but the actual risk for a particular individual may differ. It is not possible to tell a woman how long she will live with uterine cancer. Because the survival statistics are measured in multi-year intervals, they may not represent advances made in the treatment or diagnosis of this cancer.

Statistics adapted from the American Cancer Society's publication, Cancer Facts & Figures 2009.

Find out more about basic cancer terms used in this section.