Understand endometrial cancer

Endometrial cancer is the most common form of uterine cancer, so it is frequently referred to as uterine cancer.

The information on this page may help you gain better understanding of your endometrial cancer diagnosis. Being prepared may help when making important decisions with your doctor.

What is endometrial cancer?

Endometrial Cancer Stages

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 and develops when a woman is pregnant. The lower, narrow end of the uterus is the cervix, which leads to the vagina. Cancer of the endometrium is the most common cancer of the female reproductive organs in the United States. Cancer of the uterus is usually used to refer to cancers that start in the body of the uterus, not the cervix (cervical cancer is a separate kind of cancer).

Endometrial cancer mainly affects post-menopausal women, and the average age to be diagnosed with this type of cancer is 60. It is uncommon in women under the age of 45. After endometrial cancer has been treated, it may come back in the uterus, the pelvis, lymph nodes in the abdomen, or other parts of the body.

Stages of endometrial cancer

From the National Cancer Institute (NCI)

The information below is based on information originally published by the National Cancer Institute (NCI), the US government’s main agency for cancer research.

Endometrial cancer is described in 4 stages ranging from I to IV, with stage IV being the most severe. Endometrial cancer may also be grouped for treatment into low-risk endometrial cancer or high-risk endometrial cancer.

Low-risk and high-risk endometrial cancer

Endometrial cancer may be grouped for treatment as follows:

  • Low-risk endometrial cancer: Grades 1 and 2 tumors are usually considered low-risk. They usually do not spread to other parts of the body.
  • High-risk endometrial cancer: Grade 3 tumors are considered high-risk. They often spread to other parts of the body. Uterine papillary serous, clear cell, and carcinosarcoma are 3 subtypes of endometrial cancer that are considered grade 3.

Stage I (1) endometrial cancer

In stage I, cancer is found in the uterus only. Stage I is divided into stages IA and IB, based on how far the cancer has spread.

In stage IA

  • The cancer is in the endometrium only or less than halfway through the myometrium (muscle layer of the uterus).

In stage IB

  • The cancer has spread halfway or more into the myometrium.

Stage II (2) endometrial cancer

In stage II, the cancer has spread into connective tissue of the cervix, but has not spread outside the uterus.

Stage III (3) endometrial cancer

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.

In stage IIIA

  • The cancer has spread to the outer layer of the uterus and/or to the fallopian tubes, ovaries, and ligaments of the uterus.

In stage IIIB

  • The cancer has spread to the vagina and/or to the parametrium (connective tissue and fat around the uterus).

In stage IIIC

  • The cancer has spread to lymph nodes in the pelvis and/or around the aorta (largest artery in the body, which carries blood away from the heart).

Stage IV (4) endometrial cancer

In stage IV, the cancer has spread beyond the pelvis. Stage IV is divided into stages IVA and IVB, based on how far the cancer has spread.

In stage IVA

  • The cancer has spread to the bladder and/or bowel wall.

In stage IVB

  • The cancer has spread to other parts of the body beyond the pelvis, including the abdomen and/or lymph nodes in the groin.

Learn about a possible treatment option for certain patients with advanced endometrial cancer.