Uterine Cancer / Endometrial Cancer
Endometrial cancer is one of the most common cancers in American women. In fact, about 40,000 American women receive a diagnosis of endometrial cancer each year, making it the fourth most common cancer found in women — after breast cancer, lung cancer and colon cancer.
Endometrial cancer usually begins in the endometrium, the lining of the uterus — a hollow, pear-shaped pelvic organ where fetal development occurs. Endometrial cancer is most common after the reproductive years, between the ages of 60 and 70. Endometrial cancer is sometimes called uterine cancer, but there are other cells in the uterus that can become cancerous — such as muscle or myometrial cells. These form much less common cancers called sarcomas and account for less than 5 percent of uterine cancers.
Endometrial cancer is often detected at an early stage because it frequently produces vaginal bleeding between menstrual periods or after menopause. If discovered early, this slow-growing cancer is likely to be confined to the uterus. Removing the uterus surgically often eliminates all of the cancer. In fact, stage I endometrial cancer is successfully treated more than 90 percent of the time. Unfortunately, not all endometrial cancer can be successfully treated. In these cases, the cancer has spread beyond the uterus by the time it's detected. About 7,000 American women die each year of endometrial cancer.
Healthy cells grow and divide in an orderly way to keep your body functioning normally. But sometimes cells become abnormal (mutate) and grow out of control. The cells continue dividing even when new cells aren't needed. These abnormal cells can invade and destroy nearby tissues and even have the ability to travel to other parts of the body and begin growing there.
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.
The female reproductive system consists of two ovaries, two fallopian tubes, a uterus and a vagina. The ovaries produce two main female hormones — estrogen and progesterone. The balance between these two hormones changes each month, making the endometrium thicken during the early part of the monthly cycle. If no pregnancy occurs, the endometrium is then shed during the last phase of the menstrual cycle.
When the balance of these two hormones shifts toward more estrogen — which stimulates growth of the endometrium — a woman's risk of developing endometrial cancer increases. Factors that increase levels of estrogen in the body include:
- Many years of menstruation. If you started menstruating at an early age — before age 12 — and continue to have periods into your 50s, you're at greater risk of endometrial cancer than is a woman who menstruated for fewer years. The more years you have had periods, the more exposure your endometrium has had to estrogen.
- Never having been pregnant. Pregnancy seems to protect against endometrial cancer, although experts aren't sure exactly why this might be. The body produces more estrogen during pregnancy, but it produces more progesterone, too. Increased progesterone production offsets the effects of the rise in estrogen levels. Women with excess exposure to estrogen that isn't counteracted by progesterone tend to be at increased risk of endometrial cancer.
- Irregular ovulation. Ovulation, the monthly release of an egg from an ovary in menstruating women, is regulated by estrogen. Irregular ovulation or failure to ovulate can increase your lifetime exposure to estrogen. Ovulation irregularities have many causes, including obesity and a condition known as polycystic ovary syndrome (PCOS). This is a condition in which hormonal imbalances prevent ovulation and menstruation. Treating obesity and PCOS can help restore your monthly ovulation and menstruation cycle, decreasing your risk of endometrial cancer.
- Obesity. Ovaries aren't the only source of estrogen. Fat tissue can change some hormones into estrogen. Being obese can increase levels of estrogen in your body, putting you at a higher risk of endometrial cancer and other cancers. A high-fat diet also can add to your risk by promoting obesity. Some scientists even think that fatty foods may directly affect estrogen metabolism, further increasing a woman's risk of endometrial cancer.
- Diabetes. This is a risk factor for endometrial cancer mainly because obesity and type 2 diabetes often go hand in hand. However, some data suggest that women who have diabetes, whether they're obese or not, are at greater risk of endometrial cancer.
- Estrogen-only replacement therapy (ERT). Estrogen stimulates growth of the endometrium. Replacing estrogen alone after menopause may increase your risk of endometrial cancer. Taking synthetic progestin, a form of the hormone progesterone, with estrogen — combination hormone replacement therapy — causes the lining of the uterus to shed and actually lowers your risk of endometrial cancer. However, this combination may cause other health risks.
- Ovarian tumors. Some tumors of the ovaries may themselves be a source of estrogen, increasing estrogen levels.
|Other factors that can increase your risk of endometrial cancer include:
Having risk factors for endometrial cancer doesn't mean you'll get the disease. It means that you're at risk and should be alert to possible signs and symptoms of the disease. Conversely, some women who develop endometrial cancer appear to have no risk factors for the disease.
- Age. Most endometrial cancers develop over many years. Therefore, the older you are, the greater your risk. Ninety-five percent of endometrial cancer occurs in women older than 40.
- Personal history of breast cancer or ovarian cancer. Some of the same risk factors for breast cancer and ovarian cancer also increase your risk of endometrial cancer.
- Tamoxifen treatment. One in every 500 women whose breast cancer was treated with tamoxifen will develop endometrial cancer. Although tamoxifen acts mostly as an estrogen blocker, it does have some estrogen-like effects and can cause the uterine lining to grow. If you're being treated with this hormone, see your doctor for an annual pelvic examination and be sure to report any unusual vaginal bleeding.
- Race. White women are more likely to develop endometrial cancer, but black women are much more likely to die of the disease.
- Hereditary nonpolyposis colorectal cancer (HNPCC). This inherited disease is caused by an abnormality in a gene important for DNA repair. Women with HNPCC also have a significantly higher risk of endometrial cancer as well as colon and other cancers.
When to seek medical advice:
Because endometrial cancer is more likely to be successfully treated the earlier it's detected, see your doctor if you experience any signs or symptoms of the disease — including vaginal bleeding or discharge not related to your periods, pelvic pain or pain during intercourse. Many of the symptoms you experience may be associated with noncancerous (benign) conditions, such as vaginal infections, uterine fibroids or uterine polyps. But it's still important to bring them to the attention of your doctor.
If you're at increased risk of endometrial cancer, talk with your doctor about what screening tests might be appropriate for you. If you have had endometrial cancer, your doctor should outline a regular follow-up program to watch for possible recurrence.
Endometrial cancer often develops over a period of years. Your first clue that something is wrong may be abnormal vaginal bleeding.
Most cases of endometrial cancer develop in postmenopausal women, whose periods have stopped. However, a small percentage of cases affect women younger than 40.
Signs and symptoms of endometrial cancer may include:
Rarely does endometrial cancer reach an advanced stage before any signs and symptoms are present.
- Prolonged periods or bleeding between periods
- More frequent vaginal bleeding or spotting during the years leading up to menopause (perimenopause)
- Any bleeding after the time of menopause
- A pink, watery or white discharge from your vagina
- Pelvic pain, especially late in the disease
- Pain during intercourse
- Weight loss
If your doctor suspects endometrial cancer, you may be referred to a gynecologist — a doctor who specializes in conditions affecting the female reproductive system. The gynecologist or your primary care doctor will conduct a complete medical history and perform a physical and pelvic examination. During the pelvic examination, the doctor feels for any lumps or changes in the shape of the uterus that may indicate a problem.
|Diagnosis may or may not involve these other tests:
If endometrial cancer is found, you'll likely be referred to a gynecologic oncologist — a doctor who specializes in treating cancers involving the female reproductive system. You'll need more tests (staging) to determine if the cancer has spread (metastasized) to other parts of your body. These tests may include a chest X-ray, a computerized tomography (CT) scan and a blood test to measure cancer antigen 125 (CA 125), a substance that's released in the bloodstream by some endometrial and ovarian cancers.
- Pap test. Your doctor takes a sample of cells from the cervix, the lower, narrower portion of the uterus that opens into your vagina. Doctors use the Pap test to detect another type of cancer — cervical cancer. Because endometrial cancer begins inside your uterus, it's rarely detectable by a Pap test.
- Endometrial biopsy. To get a sample of cells from inside your uterus, you'll likely undergo an endometrial biopsy. This involves removing a small piece of tissue from your uterine lining for laboratory analysis. This may be done in your physician's office and usually doesn't require anesthesia.
- Dilation and curettage (D and C). If enough tissue can't be obtained during a biopsy or if the biopsy suggests cancer, you'll likely need to undergo a D and C. In this procedure, which requires you to be in an operating room under anesthesia, tissue is scraped from the lining of your inner uterus and examined under a microscope for cancer cells.
- Transvaginal ultrasound. Your doctor may recommend a transvaginal ultrasound to help rule out other conditions. In this procedure, a wand-like device (transducer) is inserted into your vagina. The transducer uses sound waves to create a video image of your uterus. This test helps your doctor look for abnormalities in your uterine lining.
In endometrial cancer, final staging is done through a surgical procedure and is done at the same time as any surgical Treatment:
- Stage I cancer is found only in your uterus and hasn't spread.
- Stage II cancer is present in both the body of your uterus and in your cervix. In this stage, cancer is no longer confined to the uterus, but hasn't spread beyond the pelvic region.
- Stage III cancer has not involved the rectum and bladder, though pelvic area lymph nodes may be involved.
- Stage IV cancer is the most serious and means that the cancer has spread past the pelvic region and can affect the bladder, rectum and other parts of your body.
Fortunately, about 75 percent of endometrial cancers are diagnosed at stage I or II.
When discovered early, endometrial cancer is usually treatable. However, in some women endometrial cancer reaches an advanced stage before diagnosis.
Endometrial cancer can cause pelvic pain and painful urination. As the cancer advances, symptoms may worsen. Treating the cancer can help alleviate the pain.
Women with endometrial cancer may lose enough blood from vaginal bleeding to cause anemia — a condition in which the blood is low in red blood cells. Anemia causes fatigue and shortness of breath. But anemia can be treated along with your cancer, helping you regain energy.
Surgery is the most common treatment for endometrial cancer. Most doctors recommend either the surgical removal of the uterus alone (hysterectomy) or, more likely, the surgical removal of the uterus, fallopian tubes and ovaries (hysterectomy with bilateral salpingo-oophorectomy). Lymph nodes in the area should also be removed during surgery along with other tissue samples.
A hysterectomy is a major operation, and because you can't get pregnant after your uterus has been removed, it can be a difficult decision for some women. However, surgery is usually the only way to eliminate the cancer or the need for further treatment.
If you have an aggressive form of endometrial cancer or the cancer has spread to other parts of your body, you may need additional treatments. These may include:
Each type of treatment for endometrial cancer can have side effects. Ask your doctor what side effects you can expect and what can be done to manage them.
- Radiation. Radiation therapy involves the use of high-dose X-rays to kill cancer cells. If your doctor believes you're at high risk of cancer recurrence, he or she may suggest that you have radiation therapy after a hysterectomy. Your doctor may also recommend radiation therapy if the cancerous tumor is fast growing, invades deeply into the muscle of the uterus or involves blood vessels. Brachytherapy is another form of radiation that involves the internal application of radiation, usually to the inner lining of the uterus. Brachytherapy has significantly fewer side effects than conventional radiation therapy does. However, brachytherapy treats only a small area of the body.
- Hormone therapy. If the cancer has spread to other parts of your body, synthetic progestin, a form of the hormone progesterone, may stop it from growing. The progestin used in treating endometrial cancer is administered in higher doses than is used in hormone replacement therapy for menopausal women. Other medications may be used as well. Treatment with progestin may be an option for women with early endometrial cancer who want to have children and, therefore, don't want to have a hysterectomy. However, this approach is not without the risk that the cancer will return. Carefully discuss this treatment with an expert in this field.
- Chemotherapy. Chemotherapy is the use of drugs to kill cancer cells. In some cases, your doctor may recommend chemotherapy for endometrial cancer. You may receive chemotherapy drugs by pill (orally) or through your veins (intravenously). These drugs enter your bloodstream and then travel through your body, killing cancer cells outside the uterus.
If you have late-stage or recurrent endometrial cancer, you may be at decreased odds for successful treatment with standard therapies. You may benefit from participating in clinical trials that provide new experimental treatment options. For more information on clinical trials, contact the National Cancer Institute at 800-4-CANCER, or 800-422-6237, or visit its Web site.
After treatment for endometrial cancer, your doctor will likely recommend regular follow-up examinations to determine whether the cancer has returned. Checkups may include a physical exam, a pelvic exam, a Pap test, a chest X-ray and laboratory tests.
Although most cases of endometrial cancer aren't preventable, certain factors can lower your risk of developing the disease. These include:
- Taking hormone therapy (HT) with progestin. Estrogen stimulates growth of the endometrium. Replacing estrogen alone after menopause may increase your risk of endometrial cancer. Taking synthetic progestin, a form of the hormone progesterone, with estrogen causes the lining of the uterus to shed. This kind of combination hormone therapy lowers your risk. But not all effects of HT are positive. Taking HT as a combination therapy can result in serious side effects and health risks. Work with your doctor to evaluate the options and decide what's best for you.
- A history of using birth control pills. Use of oral contraceptives can reduce endometrial cancer risk even as long as 10 years after you stop taking them. The risk is lowest in women who take oral contraceptives for many years.
- Maintaining a healthy weight. Obesity is one of the highest risk factors for the development of endometrial cancer in most women. You can help prevent endometrial cancer by maintaining a healthy weight. Excess fat tissue can increase levels of estrogen in your body, which increases your risk of endometrial cancer. Maintaining a healthy weight as you age lowers your risk of endometrial cancer as well as other diseases.