Uterus / Endometrium

This information should not be used for self-diagnosis or in place of a qualified physician's care.

Reviewed June 2016

The basics

Guidelines for treating this cancer have been developed by the Gynecology Tumour Group.
For health professional information on treating these cancers, please see our Cancer Management Guidelines (Endometrium).
For newly diagnosed patients, we offer Taking it Step by Step: a guide for women diagnosed with gynecological cancer. This BC guide was created by survivors and health care professionals of BC Cancer. It covers all aspects of the patient journey.
Cancer of the uterus is also called uterine cancer. Cancer of the endometrium, or endometrial cancer, is the most common type of uterine cancer and starts in the lining of the uterus, the endometrium.
Cancers that start in the muscle or connective tissue in or near the uterus are much less common and are known as uterine sarcomas.
The uterus or "womb" is part of the female reproductive system. It is the part of the body in which a baby grows and develops during pregnancy.
The uterus is a hollow organ the size and shape of an upside-down pear. It lies in the pelvis between the bladder and rectum.
The upper portion of the uterus is called the fundus or dome.
The central portion of the uterus is called the body or corpus.
The lower or neck portion of the uterus is called the uterine cervix. It provides the connection between the corpus or body of the uterus and the vagina. Please see the information on cervix cancer for more information.
The body of the uterus is made up of two layers of tissue:

The myometrium is the muscular, outer layer. It is needed to push a baby out during birth.
The endometrium is the inner layer or lining. During a woman's menstrual cycle, hormones cause the endometrium to change. Ovaries produce estrogens which cause the endometrium to thicken so that it could nourish an embryo if pregnancy occurs. If there is no pregnancy, a lower amount of estrogen is produced and more of the hormone progesterone is produced. This causes the thick, blood-rich lining of the endometrium to shed each month during a woman's menstrual period.

Cancers of the uterus are the most common cause of cancers of the female reproductive system.

What causes it and who gets it?

Listed below are some of the known risk factors for this cancer. Not all of the risk factors below may cause this cancer, but they may be contributing factors.

Cancer of the uterus usually occurs in post-menopausal women between the ages of 45 and 70.
The longer the women's body is exposed to the hormone estrogen, the greater her risk of developing cancer of the uterus.
Estrogen is produced during a woman's menstrual cycle. Women who have had more menstrual cycles are at higher risk for getting cancer of the uterus.

For example, women who began to menstruate at a young age or who have continued periods after the age of 50.
Pregnancy interrupts the menstrual cycle so that women who have never had children are more likely to get cancer of the uterus.
Women who do not ovulate during menstrual cycles are at higher risk for getting cancer of the uterus.

Women can be exposed to estrogen in other ways, too.

Women who take birth control pills that contain a combination of estrogen and progesterone have a decreased risk of developing endometrial cancer.
Obese women (especially those who have hypertension and diabetes) are at higher risk because some estrogen is produced in fatty tissue.
Estrogen therapy is used to control the symptoms of menopause. When estrogen is combined with progesterone the incidence of cancer of the uterus is lowered.

Hereditary Nonpolyposis Colorectal Cancer (HNPCC) or Lynch syndrome, a rare inherited genetic syndrome, also increases the risk of uterus cancer.
White women are affected more commonly than black.
Higher income groups are affected more often than low income groups.
Statistics

Can I help to prevent it?

Do not take estrogen alone. The combination of estrogen and progesterone therapy can help prevent cancer of the uterus.
The use of birth control pills lowers a women's chance of developing cancer of the uterus.
Your risk rises if you are moderately to significantly overweight. Together, healthy eating and regular physical activity are the best way to maintain a healthy body weight.
Follow the recommendations in Canada's Food Guide and visit the BC Cancer Agency’s Prevention page on Nutrition information and resources.
Visit the BC Cancer Agency’s Prevention page on Physical Activity for information and resources.

Screening for this cancer

No effective screening program exists for this cancer yet.
Although a routine Pap test occasionally detects patients with this disease, it will miss many of them because the Pap smear scrape does not reach the uterine cavity.
In post-menopausal women who have not had any previous abnormality of the uterine cervix, the Pap smear should include the microscopic examination of cells from the lining of the cervical canal or from vaginal wall secretions.
Promptly talk to your doctor about abnormal vaginal bleeding (particularly post-menopausal bleeding and abnormal bleeding after the age of 40).

Signs and Symptoms

Unusual vaginal bleeding is the most common symptom, such as:

Bleeding between periods
Bleeding with sexual intercourse
Heavy bleeding
Irregular or heavy bleeding during menopause or any bleeding after menopause

Unusual vaginal discharge
Difficult or painful urination
Pain in the abdomen or pelvic area
Back pain
Precancerous conditions that should be watched carefully are:

Atypical hyperplasia (an overgrowth of the cells in the lining of the uterus)
Polyps (small growths of endometrial tissue that are attached to the inner lining of the uterus. They may disappear at any stage without treatment.)

Endometriosis is a condition in which tissue resembling the uterine lining occurs inappropriately in various locations in the pelvic area. It is not a cancer.
Attention to early symptoms generally leads to an early diagnosis with a successful treatment outcome.

Diagnosis & staging

Diagnosis

These are tests that may be used to diagnose this type of cancer.

Investigations of abnormal vaginal bleeding may include :

Physical examination of the pelvic area
Endometrial biopsy – removal of a small piece of tissue from the uterine lining or endometrium to check for signs of cancer
D and C (dilation and curettage) is a procedure used to collect tissue samples from the uterine lining or endometrium. In this procedure, the opening of the cervix is enlarged (dilated) and a special instrument is used to sample the tissue on the inside of the uterus

If a cancer is strongly suspected, a surgeon may do a hysterectomy (the surgical removal of the uterus) and surgical staging (removal of the ovaries, fallopian tubes, and lymph nodes that drain the uterus) to check if there is any spread of the cancer.
Imaging such as x-rays or ultrasound, and possibly blood tests at a lab, may also be done.

For more information on tests used to diagnose cancer, see our Recommended Websites, Diagnostic Tests section.

Types and Stages

Types

Endometrial cancer (adenocarcinoma or carcinoma)

This cancer develops in the glands of the endometrium.
Subtypes of endometrial cancer include:
Endometrioid endometrial cancer

Endometrioid is the most common subtype of endometrial cancer. It occurs in 70-80% of cases.
It is confined to the uterus in approximately 85% of cases (i.e.,stage I with no distant spread).
The cure rate is very high.

Serous and clear cell endometrial cancers

Serous and clear cell endometrial cancers are rare, more aggressive subtypes of endometrial cancer.
They usually require additional therapy following surgical staging.

Adenocarcinomas

Adenocarcinoma is a common sub-type of endometrial cancer.
It is usually discovered in early stages.
If the cancer is found in stage 1, the cure rate is very high.

Uterine Sarcomas

Sarcomas are tumours that start in the muscle or connective tissue that support the uterus.
This is an uncommon type of uterine cancer.
Sarcomas can be fast growing. Patterns of spread depend on the subtype.
Subtypes of uterine sarcomas include:
Leiomyosarcoma

Leiomyosarcoma accounts for about one third of all uterine sarcomas.
Leiomyosarcomas develop in the myometrium or muscular wall of the uterus.
Spread can be distant (for example, to the lungs).

Endometrial stromal sarcoma (ESS)

This is a rare subtype which can be low or high grade.
Low grade ESS often does not require any additional therapy or can be managed with hormones only.

Malignant Mixed Mullerian Tumour (MMMT or carcinosarcoma)

Contain both glandular cells from the endometrial lining (carcinoma component) and appear to contain muscle-derived cells (sarcoma component).
Usually treated as an aggressive form of endometrial carcinoma, using the same surgical, chemotherapy and radiation guidelines.

Trophoblastic Tumours

Trophoblastic tumours are uncommon malignant tumours of the tissues that become the placenta.
The tumours may start during pregnancy, causing a miscarriage, or may start after delivery.
The tumours can grow very quickly and may spread to the lungs.
There is a high incidence in China, Mexico and the Philippines.
Protein deficiency, malnutrition and multiple pregnancies are risk factors.
These cancers are usually curable.
Subtypes: Hydatidiform mole and choriocarcinoma

Stages

Staging describes the extent of a cancer. The TNM classification system is used as the standard around the world. In general a lower number in each category means a better prognosis. The stage of the cancer is used to plan the treatment.

T describes the site and size of the main tumour (primary)

N describes involvement of lymph nodes

M relates to whether the cancer has spread (presence or absence of distant metastases)

Stage I
Tumour confined to the corpus uteri

Stage Ia

None or less than half myometrial invasion

Stage Ib

Invasion ≥ half of the myometrium

Stage II
Invades into cervical stroma

Stage III

Local and/or regional spread as specified in IIIA, B, C

Stage IIIa

Tumour involves serosa of corpus uteri or adnexae

Stage IIIb
Vaginal or parametrial involvement or pelvic peritoneum

Stage IIIc

metastases to the pelvic and/or para-aortic lymph nodes

Positive pelvic nodes

Positive para-aortic nodes

Stage IVa
Tumour invades bladder mucosa and/or bowel mucosa

Stage IVb
distant metastases

Grades
Some types of tumours are assigned a grade based on the appearance of the tumour cells and their rate of growth.

Lower grade cancer cells are usually slow growing, and under a microscope appear almost normal.

Higher grade cancer cells grow quickly, cell appearance is very different from normal cells, and they invade aggressively into surrounding tissue.

Treatment

Cancer therapies can be highly individualized – your treatment may differ from what is described below.

Cancer that is discovered before it has spread outside the uterus has the greatest chance of cure.

Surgery

For Stage I cancers, potentially curative surgery removes the uterus and cervix. The procedure is called total abdominal hysterectomy.
Bilateral salpingo oophorectomy (BSO) is surgery in which the uterus, cervix, ovaries and fallopian tubes are removed.
Surgery is important for planning any later treatments.

Radiation Therapy

Radiation can be used before surgery to shrink tumours and make them more suitable for surgery.
Radiation can also be used after surgery to try to reduce the risk of recurrence in patients with very advanced tumours.
Radiation therapy for uterus cancers might be given using an external beam, or internally with brachytherapy.

Chemotherapy

Chemotherapy may be recommended for some types, stages or grades of uterus cancer.

Hormone Therapy

Hormone therapy may be given when surgery is not feasible.
It may be used in advanced or recurrent cancer.

Follow-up after Treatment

Guidelines for follow-up after treatment are covered on our website.
You will be returned to the care of your family physician or specialist for regular followup. If you do not have a family physician, please discuss this with your BC Cancer oncologist or nurse.
Follow-up testing is based on your type of cancer and your individual circumstances.
Life after Cancer focuses on the issues that cancer survivors can face.

Reviewed Feb 2015

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