What Is Uterine and Endometrial Cancer?

Endometrial cancer is the most common form of uterine cancer. It occurs when cells on the endometrium grow abnormally. The endometrium is the thin layer of cells that lines the uterine cavity (also known as the womb). When hormonal changes occur in that lining during a woman’s menstrual cycle, cancer is able to form. When someone has uterine and endometrial cancer, these cells grow quite rapidly, ultimately invading the muscle tissue of the uterus. In some cases, they also spread outside of the uterus, into the ovaries, other areas of the abdomen, or the lymph nodes.

What are the Symptoms of Uterine / Endometrial Cancer?

Endometrial cancer occurs in about 200,000-3 million women per year, typically aged 55 and older. Symptoms indicating endometrial cancer include abnormal post-menopausal vaginal bleeding, or bleeding in between periods. Because these symptoms occur frequently, endometrial cancer is commonly discovered and diagnosed in its initial stages, which helps to ensure that it can be cured with surgery. Additional indicators are pelvic pain or pain during intercourse, although some women experience no symptoms at all.

The Six Category Classifications of Endometrial Cancer

Based on how the cells look under a microscope, endometrial carcinomas are divided into one of six main categories: Adenocarcinoma (which encompasses most endometrial cancers), Carcinosarcoma, Squamous cell carcinoma, Undifferentiated carcinoma, Small cell carcinoma, and Transitional cell carcinoma. For more information on the specific differences of these categories, visit the American Cancer Society’s website.

Doctors frequently classify endometrial carcinomas into certain categories in order to define their severity and likely causes. This is done by giving the cancer a grade. The grade is determined by evaluating the glands that the cancer forms, and comparing them to normal, healthy glands in the endometrium. When cancer forms more glands in its tissue, it is considered a lower-grade, while high-grade cancers do not form glands and present cells that are arranged in a much more scattered, haphazard way.

The Grades Of Cancer Tumors

Grade 1 tumors produce glands on 95% or more of their tissue. Grade 2 tumors produce glands on about 50-94% of their tissue. Finally, grade 3 tumors produce glands on less than half of their tissue. These cancers are termed “high-grade” and therefore have a less positive outlook than lower grade cancers when treated.

Treatments for uterine and endometrial cancer include surgical removal of the uterus, chemotherapy and radiation, and hormone therapy.

The Two Types Of Endometrial Cancer

Physicians also tend to separate endometrial cancer into two types. Type 1 is thought to be caused by the overproduction of estrogen within the uterus. This type of cancer is not typically very aggressive and is very slow to spread into other tissue. Cancers given grades 1 or 2 are considered to be type 1 endometrial cancers. Type 2 endometrial cancers make up a smaller number and experts are not yet sure of their cause. They encompass all endometrial carcinomas that are not termed type 1, and can also be called “poorly differentiated” or “high-grade.” These cancers are often more likely to spread outside of the uterine area, and therefore can have a poorer outlook. To combat this issue, doctors tend to treat type 2 endometrial cancers more aggressively.

Other Types Of Uterine Cancer

Other types of cancer can form in the uterus as well, but they are all much more rare. The other main uterine cancer is uterine sarcoma. This form is much less common than endometrial cancer. It starts in the muscle layer of the uterus rather than the inner lining, and is also medically treatable.

Treatment of Endometriosis

A common treatment plan recommended by doctors for endometriosis is removal of the uterus via a hyserectomy or removal of the fallopian tubes, via a myomectomy. However, endometriosis currently doesn’t have a cure. These procedures can reduce the probability of the condition re-occuring, however it can come back.

WARNING: Some hysterectomies and myomectomies have been performed with a tool known as the Power Morcellator. In the last year, we have been notified that this tool can be unsafe for women who have morcellation because there is a 1 in 350 chance that the woman undergoing a hysteretomy or myomectomy for removal of fibroids has leiomyosarcoma, or cancerous tissue within the fibroids, which can be spread by the morcellator, causing metastasis of cancer. For more information read our dedicated resource guide.