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Endometrial cancer (uterine cancer) is a malignant tumor (cancer) that develops in the cells of the endometrium, which is the tissue lining the uterus. Usually, an endometrial cancer is characterized by abnormal division of cells that line the inner membrane of the uterus, resulting in the formation of a cancerous growth.
Endometrial cancer is a hormone-dependent tumor; its cells depend on exogenous estrogens to divide. Therefore, treatment with exogenous estrogen is associated with the risk of having the disease. Usually, endometrial cancer occurs after menopause and is manifested primarily by vaginal discharge and bleeding along with fever and abdominal pain.
The main treatment of endometrial cancer is surgical removal of the uterus and ovaries. In some cases, radiotherapy and chemotherapy may be associated with the surgery to increase the chance of survival; unlike many other types of cancer, healing is obtained in 70 to 80% of cases of endometrial cancer.
Endometrial Cancer Statistics
Endometrial cancer is the most common cancer of the female genital tract; it is about 1.5 times more common than ovarian cancer, and 3 times more common than cancer of the cervix (cervical cancer). Endometrial cancer accounts for about 13% of all cancers in women. According to the National Cancer Institute (NCI), it is estimated that 42,160 women were diagnosed with endometrial cancer in 2009 with about 7,780 women dying of it.
Based on cases diagnosed in 2002-2006 from 17 SEER (Surveillance Epidemiology and End Results) geographic areas, the age-adjusted incidence rate for endometrial cancer was 23.3 per 100,000 women per year. Incidence rates by race were approximately:
- 24.2 per 100,000 white women
- 20.3 per 100,000 black women
- 16.8 per 100,000 Asian/Pacific Islander women
- 16.3 per 100,000 American Indian/Alaska Native women
- 17.8 per 100,000 Hispanic women
Endometrial Cancer Causes
The endometrium is a layer of cells covering the inside of the uterus. At the beginning of each menstrual cycle, it thickens to host an embryo in the timing of nidation, an organic process whereby a fertilized egg becomes implanted in the lining of the uterus. If at the end of the menstrual cycle, no embryo has implanted, much of the uterine lining peels off, thus constituting the menstrual period.
Unfortunately, sometimes those cells are not released from the body during the menstrual period and pathogenically accumulate in the uterine. Even in women who stop having their menstrual cycle (menopausal women), cells lining the inside of the uterus should naturally die to be periodically replaced by new healthy cells. Unfortunately, in some women, those cells continue to live and multiply without control. This uncontrolled cellular alteration causes the formation of a malignancy or cancerous growth in the uterine. Although the cause of endometrial cancer is not well known, scientists believe many factors can contribute to the genesis of the disease: environment, chemicals, physical aggression, and certain viruses.
Estrogen levels play a major role in the development of endometrial cancer. Although several factors may increase your estrogen levels, obesity and menopause are the two major causative factors. There is no relationship between endometrial cancer and STDs, in contrast to cervical cancer. The cancer can occur in women who have never had sexual intercourse or HPV infection. Endometrial cancer is more common among women who had few or no children and women who started menstruating at an early age.
Endometrial Cancer Risk Factors
The most common causative factors for endometrial cancer include:
- Age– The average age of endometrial cancer patients is sixty one with a majority of cases between 50-69 years. 5% of endometrial cancers are diagnosed before 40 years old, 25% before menopause. Women over fifty are more at risk of the disease.
- Race– Endometrial cancer is more common among white women living in Western countries.
- Infertility– If you have not had children, you have three to eight times more chance to develop endometrial cancer compared to women who have.
- High estrogen levels– Endometrial cancer is hormone-dependent; therefore, its occurrence is favored by high estrogen levels in the blood.
- Certain diseases– Certain medical conditions such as diabetes, hypertension, under active thyroid, and disorder of the gallbladder increase the risk of developing endometrial cancer.
- Endometrial disease– If you have endometrial hyperplasia, your risk to have endometrial cancer increases.
- Family history– If you have a personal or family history of endometrial cancer or colon cancer, you are at greater risk.
- Overweight– Your body produces some of its estrogen in the fatty tissues; therefore, obesity or excess weight can cause an increased production of estrogen, which may contribute to the occurrence of endometrial cancer.
- Estrogen-only replacement therapy– Hormone replacement therapy consists of estrogen without progesterone and increases the risk of developing endometrial cancer in a ratio of approximately 120% for each period of five years of use. However, when estrogen is associated with progesterone, the therapy is safe.
- Early first menstruation or late menopause– If you had your first menstruation at a young age (before age 12) and are going through menopause at a late age, you are at greater risk of becoming an endometrial cancer victim.
- Physical inactivity– Sedentary lifestyle is the enemy of your body. It causes excess weight, cardiovascular problems, and much more. Physical activity, on the other hand, controls the production of estrogen produced by the ovaries and reduces the risk of endometrial cancer.
- Certain medications– If you have been treated with tamoxifen to prevent or treat breast cancer, you have twice the risk of developing endometrial cancer.
- Fatty foods– Besides endometrial cancer, consumption of foods rich in unhealthy fats and red meat are likely to cause many cancers.
Endometrial Cancer Symptoms
Since endometrial cancer develops, in most cases, in postmenopausal women, early symptoms are most often bleeding or unusual discharge from the vagina. While other health problems can lead to abnormal vaginal bleeding, in postmenopausal women it is a red flag.
Fortunately, unlike many other types of cancer, symptoms of endometrial cancer usually appear early; therefore, the mortality rate of endometrial cancer is low.
In general, if you have endometrial cancer, you will experience at least one of the following symptoms:
- weight loss
- abnormal bleeding after menopause
- vaginal discharge
- bleeding between periods (premenopausal women)
- difficult or painful urination
- painful sexual intercourse
- pain in the pelvic, back and sometimes in the leg
Endometrial Cancer Complications
Endometrial cancer, detected early, rarely causes complications. In fact, five-year survival rates of endometrial cancer are nearly 95 percent. However, late diagnosis does not bring good results. The cancer spreads to other parts of the body to form other cancers called metastasis. This condition is called metastatic endometrial cancer. In this case, the cancer is more difficult to be treated and survival chance decreases.
Endometrial Cancer Diagnosis
Your doctor can start the diagnosis by asking you questions about your medical history and the symptoms you experience. In addition, your physician can do a physical examination to examine your abdomen and pelvic area to look for signs that indicate endometrial cancer.
However, for women who are close to menopause and have regular menstruation, the diagnosis is more difficult. There may be menorrhagia (heavier bleeding) or bleeding unrelated to cancer. To rule out non-cancerous bleeding, your doctor will do a pelvic examination with a small speculum to directly visualize the cervix. In the absence of cancer, these tests usually show a normal cervix.
However, a pelvic exam is not enough to confirm the presence of a cancer in your endometrium. The following tests will be recommended:
- Pap test– This test is done to look inside the vagina and at the outside of the uterus. During the test, your physician can introduce a speculum into your vagina to take sample of cells from the cervix for a microscopic exam. A Pap test (Pap smear) may not reveal an endometrial cancer, but it is a key procedure used to detect suspicious anomalies that can lead to cancer.
- Transvaginal ultrasound– This painless medical technique consists of inserting two or three inches of the tip of a transducer in your vagina to visualize the reproductive organs, which are the uterus, ovaries, cervix, and vagina. This test allows your doctor to obtain images of these organs from different angles and detect the development of an endometrial cancer. Usually, if the test reveals any cancerous lesion, your physician will perform a biopsy to accurately confirm the disease.
- Biopsy– Although others methods may reveal an endometrial cancer, a biopsy is usually necessary to establish with certainty the diagnosis. During the procedure, your doctor removes a small piece of tissue from your endometrium for laboratory analysis. If cancer cells are found, other techniques will be performed to determine the speed of the cells to multiply.
Although rare, an endometrial biopsy may lead to complications such as infections, bleeding or uterine perforation. If you experience pain or bleeding after the biopsy, see your doctor immediately.
- Dilation and curettage (D and C)– This medical technique allows your health care provider to evacuate or gradually open your cervix for analysis purpose. In general, dilation and curettage is performed under local or general anesthesia; it is usually recommended in case if enough tissue was not obtained during the biopsy. Your doctor scrapes the lining of the uterus to collect tissue samples. The sample will then be examined under a microscope to look for cancer cells.
Dilatation and curettage often causes pain similar to menstrual cramps one or two days after the surgery. If these problems persist for more than three days, see your doctor immediately.
- Laparotomy– Laparotomy is a surgical procedure that can be done during an endometrial cancer diagnosis to determine the severity of the tumor. During the surgery, your surgeon makes an incision in your abdomen to explore the abdomen organs. Performed under general anesthesia, a laparotomy allows your surgeon to visualize and evaluate the tumor, surrounding tissue and lymph nodes. Laparotomy can also allow your physician to measure the extent of the tumor and whether it has spread to other organs.
- Hormone test– Although rarely performed before the treatment, your doctor may recommend a hormone test to search for estrogen receptors because endometrial cancer cells grow better in a high-estrogen environment. A positive result indicates that hormone therapy can have a positive effect against the cancer.
Endometrial Cancer Stages
Once the cancer is found in your uterine, your doctor will do some tests, which will determine the stage of the cancer. In general, stages of endometrial cancer include:
- Stage I – The cancer is localized only in the uterus; it has not spread to other tissue.
- Stage II – A stage 2 endometrial cancer usually affects both the uterus and cervix, but has not spread into the pelvic region.
- Stage III – The cancer has spread outside the uterus to reach other organs such as rectum, bladder, and lymph nodes housed in the lower abdomen (pelvis).
- Stage IV – Stage IV is the most advanced stage of the cancer; the cancer has spread to the upper abdomen and may affect not only the bladder and rectum, but also distant organs from the pelvic.
- Recurrent – A cancer that has returned after treatment is considered a recurrent cancer. In general, recurrent cancers are more difficult to be treated, and have low survival chances.
Endometrial Cancer Treatment
Most of the times, treatment of endometrial cancer consists of surgery, radiotherapy, hormone therapy, and chemotherapy. However, the treatment varies depending on your age, general health, and the stage and/or the location of the metastasis. Your doctor can use a combination of these therapies to increase your chance of recovery.
Surgical treatment
Surgery is considered the essential treatment of endometrial cancer; it is the safest medical procedure to eliminate the tumor. Depending on the stage of the cancer, your surgeon may perform a hysterectomy (removal of all or part of the uterus), or a hysterectomy with bilateral salpingo-oophorectomy (TAH-BSO), which is the removal of the uterus along with the vagina, cervix, fallopian tubes, and ovaries.
TAH-BSO is usually done under general anesthesia and requires a hospital stay. Although this method is new and less common, your surgeon can perform a laparoscopic surgery to remove the tumor.
Laparoscopic surgery – Also called minimally invasive surgery (MIS), a laparoscopic surgery is a recent surgical technique consisting of operating on an organ of the abdomen through small incisions. This method allows quicker recovery than other abdominal surgeries that involve large cuts.
However, any surgical method performed involving removal of your uterus will make you unable to conceive. Talk to your surgeon if you plan to get pregnant in the future.
For a stage I endometrial cancer, surgery is sometimes the only treatment necessary. In advanced or metastatic cancer, however, chemotherapy, radiotherapy, or hormone therapy may be associated with the surgery.
Radiotherapy (radiation therapy)
In case of endometrial cancer stages II, III or IV, surgery must be followed by radiation therapy to destroy the cancerous cells locally and reduce the risk of recurrence or metastasis. In rare cases, radiotherapy can be administered before surgery in order to reduce the size of the tumor to facilitate the removal. In general, your physician will recommend internal radiotherapy or external radiation therapy; sometimes, both methods are used.
External beam radiation therapy – This form of radiotherapy involves projecting high-doses of X-rays to the tumor and a small amount of surrounding healthy cells to kill cancer cells or slow their multiplication. External radiation therapy is usually administered five days a week for several weeks or months.
Internal radiation therapy – In this form of radiotherapy, the radiation is placed very close to or inside the tumor. During an endometrial cancer internal radiation therapy, the radioactive materials (wires, plastic tubes, ribbons, capsules, or seeds) are inserted into the vagina for several hours to several days. The internal radiation therapy always requires hospitalization.
Chemotherapy
Chemotherapy involves use of a combination of powerful chemical substances (drugs) to kill cancer cells. Chemotherapy is recommended in the treatment of endometrial cancer, if the cancer is very aggressive -a cancer that spreads very quickly or has spread beyond the endometrium. In the treatment of endometrial cancer, chemotherapy drugs are usually administered intravenously to navigate the bloodstream to reach all parts of the body. Your doctor may administer several medications (polychemotherapy) at the same time to facilitate the destruction of the cancerous cells.
However, the chemotherapy drugs attack both the tumor cells and normal cells, causing side effects. Adverse effects most commonly associated with endometrial cancer drugs include:
- nausea
- vomiting
- fatigue
- low blood cells count
- stomach pain and vomiting
- loss of appetite
- temporary hair loss
- increased vulnerability to infections
Hormone therapy
In case the cancer has spread into your body, you can be recommended to take hormone drugs to stop the tumor from growing. Like chemotherapy, hormonetherapy is a systemic therapy that affects your entire body. Hormone therapy in the treatment of endometrial cancer usually involves taking synthetic progestin to stop the proliferation of cancer cells. If your doctor thinks it will be helpful, he can prescribe you gonadotropin-releasing hormone agonists to lower your estrogen levels.
Hormone herapy is most often used to treat advanced or recurrent cancers of the endometrium. Some of their side effects include:
- increased risk of heart disease and breast cancer
- depression
- weight gain
- fluid retention and edema
- increased risk of blood clots
- anxiety and nervousness
- hair loss
- skin disorders
- headaches
- thyroid problems
Endometrial Cancer Survival
Unlike many other cancers, endometrial cancer can have a good prognosis. Because it is often found early, the cancer is often treated successfully by surgical treatment.
The overall five-year relative survival rate for years 1999-2005 was 82.9%. The survival rate varies by race. During that same period (1999-2005), five-year relative survival rates by race were:
- 84.7% for white women
- 61.3% for black women
Endometrial Cancer Prevention
Endometrial cancer is not attributable to a unique cause but, several factors are suspected in the development of the disease. Some risk factors such as age and menopause are unpreventable. To reduce your risk of endometrial cancer, you can take the following steps:
Avoid smoking – In addition to endometrial cancer, smoking can also increase the risk of kidney cancer, bladder cancer, lung cancer, colon and rectum cancer, cervical cancer, pancreas cancer, stomach cancer, and cancers of esophagus, larynx, nasal and oral cavities.
Adopt a healthy diet – There is a correlation between endometrial cancer and consumption of saturated fats, especially animal fats and fried foods. A diet rich in fruits, vegetables, and cereals (especially high in beta-carotene) reduces the risk of endometrial cancer and many other cancers.
Exercise regularly – Many studies have shown that physical activities such as walking reduce the risk of several types of cancer including endometrial cancer after menopause. However, correlation between physical inactivity and endometrial cancer is not yet clear.
Maintain a healthy weight – It is shown in many studies that being overweight plays a major role in the development of all cancers. A Dutch epidemiological researcher that followed 25,000 women aged 40-65 years for over thirteen years found that being overweight among postmenopausal women is one of the two main risk factors for endometrial cancer and endometrial hyperplasia.
Limit intake of estrogen – If you are obligated to take hormone therapy to reduce menopause symptoms, it is better that you take medications containing progesterone which helps counteract the negative effect of estrogen.
Limit your alcohol intake – Moderate consumption of alcohol poses no risk of cancer. Heavy consumption is a causative factor for many cancers including endometrial cancer.