Information on Endometrial Cancer

Dear Readers,
In the text that follows are notes that I made from several reliable medical websites about endometrial cancer. I think, in light of recent events, that it is very important to know the risk factors of this cancer [as well as the risk factors and symptoms of any cancers]. The websites that I used to compile the following information on endometrial cancer are good sources of information on other types of cancer as well. Please note that this information is incomplete as it appears on the web sites, and that if you would like to see more complete information you should go to the websites for full text. As it relates to possible symptoms of endometrial/uterine cancer, I have also included information on DUB. I hope that this information is helpful.
Sincerely,
Laura Beth


Notes from the National Cancer Institute Website:


Women should not assume that abnormal vaginal bleeding is part of menopause.

Benign Conditions of the Uterus

• Fibroids are common benign tumors that grow in the muscle of the uterus. They occur mainly in women in their forties. Women may have many fibroids at the same time. Fibroids do not develop into cancer. As a woman reaches menopause, fibroids are likely to become smaller, and sometimes they disappear.

Usually, fibroids cause no symptoms and need no treatment. But depending on their size and location, fibroids can cause bleeding, vaginal discharge, and frequent urination. Women with these symptoms should see a doctor. If fibroids cause heavy bleeding, or if they press against nearby organs and cause pain, the doctor may suggest surgery or other treatment.

• Endometriosis is another benign condition that affects the uterus. It is most common in women in their thirties and forties, especially in women who have never been pregnant. It occurs when endometrial tissue begins to grow on the outside of the uterus and on nearby organs. This condition may cause painful menstrual periods, abnormal vaginal bleeding, and sometimes loss of fertility (ability to get pregnant), but it does not cause cancer. Women with endometriosis may be treated with hormones or surgery.

• Endometrial hyperplasia is an increase in the number of cells in the lining of the uterus. It is not cancer. Sometimes it develops into cancer. Heavy menstrual periods, bleeding between periods, and bleeding after menopause are common symptoms of hyperplasia. It is most common after age 40.

To prevent endometrial hyperplasia from developing into cancer,

Hormone Therapy

Based on solid evidence, giving progestin in combination with estrogen therapy eliminates the excess risk of endometrial cancer associated with unopposed estrogen among postmenopausal women who have a uterus and are taking hormone therapy.

Description of the Evidence

• Study Design: Evidence obtained from randomized controlled trials, cohort, and case-control studies.

• Internal Validity: Good.

• Consistency: Good.

• Magnitude of Effects on Health Outcomes: For women with a uterus, the risk of endometrial cancer associated with unopposed estrogen use for 5 or more years is more than tenfold higher compared with women not taking estrogen replacement therapy. The addition of progestin therapy to estrogen eliminates the risk of endometrial cancer. Based on data from the Women’s Health Initiative, the hazard ratio for endometrial cancer associated with combined hormone therapy, after an average follow-up of 5.6 years was 0.81 (95% confidence interval, 0.48–1.36) compared with women randomly assigned to placebo.

• External Validity: Good.

Oral Contraceptives

Based on solid evidence, the use of combination oral contraceptives (estrogen plus a progestin) is associated with a decreased risk of developing endometrial cancer.

Description of the Evidence

• Study Design: Evidence obtained from case-control and prospective studies.

• Internal Validity: Good.

• Consistency: Good.

• Magnitude of Effects on Health Outcomes: Oral contraceptive use is associated with a reduced risk of endometrial cancer ranging from 50% reduction associated with 4 years of use up to 72% reduction in risk with 12 or more years of use.

• External Validity: Fair.

Obesity, Body Mass Index and Endometrial Cancer

There is inadequate evidence to determine if weight reduction alters the incidence of endometrial cancer.

Description of the Evidence

• Study Design: Evidence obtained from one cohort study.

• Internal Validity: Good.

• Consistency: N/A

• Magnitude of Effects on Health Outcomes: Intentional weight loss of 20 pounds or more was not associated with a statistically significant reduction in the incidence of endometrial cancer.

• External Validity: Fair.



Notes from HealthCommunities.com

Adenocarcinoma, which originates in surface cells of the endometrium, accounts for approximately 90% of cases of endometrial cancer. Adenocarcinomas are more common during perimenopause (i.e., transitional years preceding and following actual menopause) and usually are associated with an early onset of symptoms.

Other types of endometrial cancer include papillary serous carcinoma and clear cell carcinoma. These types usually develop in postmenopausal women and are more likely to metastasize (spread) and recur.

Causes and Risk Factors

The cause of uterine cancer is unknown. Chronic exposure to estrogen (i.e., a female hormone produced by the ovaries) increases the risk for developing the disease and estrogen often affects tumor growth. The following factors increase estrogen exposure:

• Early menarche (beginning menstruation before age 12)

• Hormone replacement therapy (HRT) with exogenous estrogen (i.e., without progesterone)

• Late menopause (after age 52)

• Presence of an estrogen-secreting tumor (e.g., some types of breast cancer)

• Nulliparity (having never given birth) or low parity

Endometrial hyperplasia is a condition that increases the risk for uterine cancer. About one-third of patients with hyperplasia develop endometrial cancer. Symptoms of endometrial hyperplasia include heavy or prolonged menstrual periods, bleeding between menstrual periods, and prolonged amenorrhea (i.e., absence of menstruation for longer than 90 days). Postmenopausal women with hyperplasia may experience vaginal bleeding or spotting.

Long-term use of tamoxifen (e.g., Nolvadex®) increases the risk for uterine cancer. Tamoxifen is used to treat breast cancer and to decrease the risk for the disease in certain high-risk patients. Women undergoing treatment with tamoxifen are monitored carefully for uterine abnormalities.

Medical conditions such as obesity, gall bladder disease, diabetes mellitus, and high blood pressure (hypertension) increase the risk for cancer of the uterus.

Other risk factors include the following:

• Age (more common after age 50)

• Family history of uterine cancer

• Personal history of breast, colorectal, or ovarian cancer

• Prior pelvic radiation therapy

• Race (endometrial cancer is more common in Caucasian women and uterine sarcoma is more common in African American women)

Signs and Symptoms

Early uterine cancer usually is asymptomatic (i.e., does not cause symptoms). Abnormal vaginal bleeding, which is the most common symptom, may also result from a condition called dysfunctional uterine bleeding (DUB).

Other symptoms of uterine cancer include the following:

• Abnormal vaginal discharge

• Painful or difficult urination

• Pelvic pain

• Pain during intercourse

Overview DUB (information about DUB follows here)

Dysfunctional uterine bleeding (DUB) is heavy or irregular menstrual bleeding that is not caused by an underlying anatomical abnormality, such as a fibroid, lesion, or tumor. DUB is the most common type of abnormal uterine bleeding.


Most cases of DUB are associated with anovulatory bleeding (menstruation that occurs without ovulation). Anovulatory bleeding is common in women who have just started menstruating and during the several years preceding menopause. When ovulation does not occur, the level of estrogen and progesterone in the uterus is disturbed, leading to DUB. Anovulation, however, does not always lead to DUB and there are other causes as well. Women with ovulatory cycles (cycles that involve ovulation) may also experience DUB.

Menstrual cycles vary in duration, frequency, and intensity, making abnormalities difficult to determine. Women who have DUB may experience a variety of patterns of bleeding. A woman who bleeds for longer than a week, bleeds more than every 3 weeks or so, bleeds between periods, or bleeds excessively should see a doctor or other health care provider.

DUB is usually painless. Diagnosis involves ruling out other causes of abnormal bleeding. Treatment depends on the intensity and timing of the bleeding, the patient's age, and if she is trying to conceive.

Anovulatory bleeding

Normally during the menstrual cycle, the production of progesterone in the latter 2 weeks of the cycle balances out the regenerative effects of estrogen, halting further endometrial growth. In anovulation, the level of estrogen does not decline, and progesterone is not secreted to balance out the effects of estrogen.

Endometrial growth does not stop and the endometrial tissue accumulates and thickens, resulting in abnormally heavy bleeding. Also, without progesterone, the endometrium lacks structural support and sloughs off irregularly, causing heavy and/or irregular periods.

Anovulatory periods are common in the 2 or 3 years following menarche (first menstrual period) and during the several years preceding menopause. Up to 80% of menstrual cycles are anovulatory during the first year following menarche. As a woman approaches menopause, she may have 8 to 10 anovulatory periods a year.

Women who take oral contraceptives and those on estrogen replacement therapy may also have anovulatory cycles. Stress and illness can also trigger anovulation.

Causes

Ovulatory DUB (not associated with anovulation) is less common than anovulatory DUB, and the bleeding, though abnormally heavy, is usually regular.

Ovulatory DUB may be due to abnormalities in the 2-week luteal phase of menstruation that occurs just before bleeding begins. It can also result from an "atrophic endometrium" that can result from a high progesterone to estrogen ratio, which may occur in women who take progesterone-only contraceptives. A lack of cell-building estrogen causes the endometrium to slough off and bleed irregularly.

Patterns of abnormal uterine bleeding

DUB can result in the following menstrual patterns:

• polymenorrhea (frequent, regular periods that occur less than every 21 days)

• hypermenorrhea (excessively heavy bleeding during a normal-length period)

• menorrhagia (prolonged or excessive bleeding lasting longer than a week that occurs at regular intervals)

• metrorrhagia (periods that occur at irregular intervals, or frequent bleeding of various amounts,though not heavy)

• menometrorrhagia (frequent, excessive, and prolonged bleeding that occurs at irregular intervals)

Diagnosis

In women older than 35, the endometrial cells are examined under a microscope to rule out endometrial hyperplasia and cancer. This is usually done using endometrial biopsy, an outpatient procedure that involves inserting a narrow tube into the uterus through the vagina and suctioning out a small amount of tissue from several areas of the uterine wall. The procedure takes only minutes.

Endometrial biopsy is the most widely used and most effective diagnostic test for detecting precancerous and cancerous cells on the endometrium. A procedure known as a D & C (dilation and curettage) may be used in certain circumstances and involves dilating the cervix and inserting an instrument called a curette into the uterus through the vagina. The curette is used to scrape the uterine wall and collect tissue. It is an outpatient procedure that takes about an hour and requires anesthesia.

The tissue is sent to a laboratory, examined under a microscope, and evaluated for cancerous or precancerous abnormalities. Please go to endometrial cancer for more information.

If the biopsy or D & C reveals no abnormality, the patient is treated for DUB, usually with hormones.

BACK TO ENDOMETRIAL CANCER

Advanced uterine cancer may cause weight loss, loss of appetite, and changes in bladder and bowel habits. (***** aha)

NOTES FROM THE MAYO CLINIC WEBSITE

In endometrial cancer, cancer cells develop in the lining of the uterus. Why these cancer cells develop isn't entirely known. However, scientists believe that estrogen levels play a role in the development of endometrial cancer. Factors that can increase the levels of this hormone and other risk factors for the disease have been identified and continue to emerge. In addition, ongoing research is devoted to studying changes in certain genes that may cause the cells in the endometrium to become cancerous.

NOTES FROM CANCER.ORG

Family history

Endometrial cancer tends to run in some families. Some of these families also have an inherited tendency to develop colon cancer -- this disorder is called hereditary nonpolyposis colon cancer (HNPCC). Another name for HNPCC is Lynch syndrome. In most cases, this disorder is caused by a defect in either the gene MLH1 or the gene MSH2. But at least 5 other genes can cause HNPCC: MLH3, MSH6, TGBR2, PMS1, and PMS2. An abnormal copy of any one of these genes reduces the body's ability to repair damage to its DNA. This results in a very high risk of colon cancer, as well as a high risk of endometrial cancer. Women with this syndrome have a 40% to 60% risk of developing endometrial cancer sometime during their lives. The risk of ovarian cancer is also increased.

If you have colon cancer or endometrial cancer in several family members, you might want to think about having genetic counseling and testing for HNPCC. Genetic testing can help determine if you or members of your family have a high risk of getting endometrial cancer. If you do, you will need to be watched carefully for endometrial cancer. American Cancer Society guidelines recommend that women with known or suspected (based on family history) HNPCC consider beginning endometrial sampling at age 35 and that their doctors offer this test to them and explain its benefits, risks, and limitations.

Another option for a woman who has (or may have) HNPCC is to have the uterus removed once she is finished having children.

There are some families that have a high rate of only endometrial cancer. These families may have a different genetic disorder that hasn't been discovered, yet.

Although these factors increase a woman's risk for developing endometrial cancer, they do not always cause the disease. Many women with one or more of these risk factors never develop endometrial cancer. Some women with endometrial cancer do not have any of these risk factors. Even if a woman with endometrial cancer has one or more risk factors, there is no way to know which, if any, of these factors was responsible for her cancer.

Do We Know What Causes Endometrial Cancer?

We do not yet know exactly what causes most cases of endometrial cancer, but we do know that there are certain risk factors, particularly hormone imbalance, for this type of cancer. A great deal of research is going on to learn more about the disease. We know that most endometrial cancer cells contain estrogen and/or progesterone receptors on their surfaces. Somehow, interaction of these receptors with their hormones leads to increased growth of the endometrium. This can mark the beginning of cancer. The increased growth can become more and more abnormal until it develops into a cancer.

As noted in the previous section about risk factors, many of the known endometrial cancer risk factors affect the balance between estrogen and progesterone in the body.

Scientists are learning more about changes in the DNA of certain genes that occur when normal endometrial cells become cancerous. Some of these are discussed in the section, "What's new in endometrial cancer research and treatment?"

Last Medical Review: 10/

Can Endometrial Cancer Be Prevented?


Most cases of endometrial cancer cannot be prevented, but there are some things that may lower your risk of developing this disease.

One way to lower endometrial cancer risk is to change risk factors whenever possible. For example, weight loss may reduce the risk of this type of cancer in those who are obese. Controlling diabetes may also help reduce the risk. If you have any of these conditions, discuss them with your doctor.

A healthy diet and exercise can also lower endometrial cancer risk. Women who exercise on a daily basis can cut their risk in half compared to women who don't exercise. As mentioned in the risk factor section, maintaining a healthy body weight can substantially reduce your risk for this cancer.

Estrogen to treat the symptoms of menopause is available in many different forms like pills, skin patches, creams, and vaginal rings. If you are thinking about using estrogen for menopausal symptoms, ask your doctor about how it will affect your risk of endometrial cancer. Progestins (progesterone-like drugs) can reduce the risk of endometrial cancer in women taking estrogen therapy, but this combination increases the risk of breast cancer. If you still have your uterus and are taking estrogen therapy, discuss this issue with your doctor.

Getting proper treatment of pre-cancerous disorders of the endometrium is another way to lower the risk of endometrial cancer. Most endometrial cancers develop over a period of years. Many are known to follow and possibly start from less serious abnormalities of the endometrium called endometrial hyperplasia (see the section, "What are the risk factors for endometrial cancer?"). Some cases of hyperplasia will go away without treatment. Sometimes hyperplasia needs to be treated with hormones or even surgery. Treatment with progestins and a dilation and curettage (D & C) or hysterectomy can prevent hyperplasia from becoming cancerous. (D & C is described in the section, "How is endometrial cancer diagnosed?") Abnormal vaginal bleeding is the most common symptom of endometrial pre-cancers and cancers, and it needs to be reported and evaluated right away.

Last Medical Review: 10/22/2009

Last Revised: 10/22/2009