What is advanced endometrial cancer?

Endometrial cancer is a type of cancer that begins in the uterus, a hollow organ that is part of the female reproductive system. Also called the womb, the uterus is where a fetus develops and grows during pregnancy. This organ is roughly the size and shape of a pear (when a person is not pregnant).

Endometrial cancer (endometrial carcinoma) is one of the most common cancers in the United States, and it is the most common type of cancer that affects the female reproductive system.

How does endometrial cancer begin?

The uterus has three main layers, each made up of different types of tissue:

• A protective outer layer of serosa membrane, a type of smooth tissue that covers the major organs in the chest and abdomen.
• The middle layer, called the myometrium, which is a thick layer of muscle.
• The inner lining, called the endometrium. This is the tissue that is shed during menstruation (if a person is not pregnant) and where a fertilized egg attaches when a person becomes pregnant.

Endometrial cancer begins in the cells that make up the endometrium. Like other cells throughout the body, endometrial cells follow a carefully regulated lifecycle. Changes to the DNA of these cells cause changes to that lifecycle, resulting in abnormal cells that reproduce at a faster rate and expire at a slower rate.

As these abnormal cells reproduce, they can form tumors, grow into nearby tissues and organs, and spread to other areas of the body.

Non-endometrial cancers in the uterus

In addition to endometrial cancer, there is uterine sarcoma. Sarcomas are cancers that begins in muscles or connective tissues. Uterine sarcoma is rare compared to endometrial cancers. There is also a rare type of uterine cancer called uterine carcinosarcoma, which is a mix of endometrial cancer and sarcoma.

There are also cancers that affect the cervix, the bottom part of the uterus. While the cervix is part of the uterus, cervical cancer is categorized as a separate type of cancer.

What causes endometrial cancer?

Mentioned above, endometrial cancer is caused by changes to the endometrial cells. However, it’s unknown exactly what causes the changes to endometrial cells that cause some people to develop endometrial cancer.

Estrogen is a group of hormones that regulate the development and health of the female reproductive organs. While the causes of endometrial cancer are not fully understood, exposure to high levels of estrogen is believed to be a significant contributing factor to many cases of endometrial cancer. Examples include obesity and estrogen replacement therapy to treat menopause-related symptoms. (However, taking estrogen with a hormone called progesterone helps reduce the risk of uterine cancers).

Other risk factors for endometrial cancer include type 2 diabetes, history of endometrial hyperplasia, family history of endometrial cancer or colorectal cancer, the use of an intrauterine device (IUD), radiation therapy to the pelvis to treat another cancer, and polyendocrine metabolic ovarian syndrome (PMOS)—a condition previously known as polycystic ovary syndrome (PCOS).

What is advanced endometrial cancer?

Advanced cancers generally refer to cancers that cannot be fully cured, though there is no official medical definition of the term “advanced cancer,” and the meaning of the term can shift depending on the type of cancer being described.

You may come across the term “advanced endometrial cancer” when learning about endometrial cancer or learning about a diagnosis. Advanced endometrial cancer may refer to:

• A locally advanced cancer, where the primary tumor has grown outside the uterus into nearby tissues, or spread to nearby lymph nodes.
• A metastatic cancer, which has spread to distant sites in the body.

Recurrent and high-risk cancers are sometimes listed alongside advanced endometrial cancer, since treatment recommendations can overlap between advanced, recurrent, and high-risk cancers.

• Recurrent cancer, cancer that has returned and/or progressed after treatment.
• High-risk cancers. High-risk cancers that are typically more aggressive, and more likely to spread and recur.

If you have questions about your diagnosis, ask your healthcare team. While endometrial cancer is common, every case is somewhat unique, and your healthcare providers will be your best source of information about your diagnosis and the different factors that need to be considered when making treatment decisions.