What is cancer of the uterus?
The uterus (womb) is a hollow, pear-shaped organ located in a woman's lower abdomen between the bladder and the rectum. The narrow, lower portion of the uterus is the cervix; the broader, upper part is the corpus. The corpus consists of muscle tissue (myometrium), which surrounds the uterine cavity. The myometrium increases in size during pregnancy to hold the growing foetus. The uterine cavity is covered with a lining (endometrium).
In women of childbearing age, the endometrium goes through a series of monthly changes known as the menstrual cycle. Each month, endometrial tissue grows and thickens in preparation to receive a fertilised egg. If fertilisation does not occur during a particular cycle, the endometrium is broken down and the tissue is passed together with blood as menstruation through the cervix and vagina. Cancer of the womb can either develop from the surface of the cervix (cervical cancer) or it can develop in the endometrium (endometrial cancer). In this section, we will concentrate on endometrial cancer, which is also referred to as uterine cancer or cancer of the corpus.
Researchers study patterns of cancer in the population to discover which people are more likely to develop certain cancers and what aspects of our surroundings and lifestyles may cause cancer.
Cancer of the uterus occurs most often in women between the ages of 55 and 70. This disease accounts for about 6 percent of all cancers in women. Research shows that some women are more likely than others to develop cancer of the uterus. These women are said to be "at risk." Obese women who are 20 kg overweight have a tenfold increase in risk to develop endometrial carcinoma. Women who have few or no children, women who began menstruating at a young age, those who had a late menopause, and women of high socioeconomic status are also at increased risk of developing this disease. It appears that most of the risk factors for cancer of the uterus are related to hormones, especially excess oestrogen.
Studies have shown that women taking oestrogen replacement therapy (ERT) for menopausal symptoms have a two to eight times greater risk of developing uterine cancer compared to women who do not take oestrogens. The risk increases after 2 to 4 years of use and seems to be greatest when large doses are taken for long periods of time. A woman who takes ERT after her uterus has been removed is in no danger of developing uterine cancer.
In women who still have their uterus, doctors now use a combination of oestrogens and progestogens (the equivalent of another female hormone normally produced by the ovaries during the second half of the cycle) as hormone replacement therapy (HRT). This decreases the risk of cancer of the uterus since the progestogens block the receptors for oestrogens in the endometrium. It is especially important for all women taking HRT to be checked regularly for any signs of cancer. Unusual bleeding should be reported to the doctor at once.
Certain forms of endometrial cancer have a strong genetic link. Some families may have defective genes that make the members of that family more prone to the development of cancer. One such familial disease is associated with colon (large intestine) cancer and endometrial cancer that occur at a young age in many members of one family.
Recent evidence shows that the use of birth control pills may decrease the risk of developing uterine cancer later. Women who use a combination pill (containing both oestrogen and progestogen in each pill) for at least one year have only half the risk of endometrial cancer when compared to women who use other types of birth control pills or none. The longer a woman takes the combination pill, the more this protection increases.
Other forms of contraception may also protect against endometrial cancer. The long lasting injectable contraceptives like Depo provera and Nur isterate have a significant protective effect.
What are the symptoms?
Postmenopausal bleeding, which is any bleeding 6 months after menopause, is the most common symptom of cancer of the uterus. Bleeding may begin as a watery, blood-streaked discharge. Later, the discharge may contain more blood.
Cancer of the uterus does not often occur before menopause, but it may occur around the time menopause begins. The reappearance of bleeding should not be considered simply part of menopause; it should always be checked by a doctor.
Abnormal bleeding is not always a sign of cancer. It is important for a woman to see her doctor, however, because that is the only way to find out what the problem is. Any illness should be diagnosed and treated as soon as possible, but early diagnosis is especially important for cancer of the uterus.
When symptoms suggest the possibility of uterine cancer, a medical history is taken and a thorough examination is conducted. In addition to checking general signs of health (blood pressure, weight, sugar in the urine and so on), the doctor usually performs one or more of the following examinations:
- Gynaecological examination: A speculum is first used to widen the opening of the vagina so that the doctor can look at the upper portion of the vagina and at the cervix. This is followed by a thorough examination of the uterus, ovaries, bladder, and rectum by bimanual palpation. The doctor feels these organs for any abnormality in their shape and size.
- Pap smear: During speculum examination, a Pap smear is taken to detect cancer precursors or cancer of the cervix if the patient did not have a normal Pap test recently. While it is sometimes possible to identify cancer cells from the uterine cavity on a Pap smear, this test is not a reliable screening method for uterine cancer because it cannot always detect abnormal cells from the endometrium.
- Ultrasound: A sonarprobe is covered with a sterile condom, lubricated with a special sonar jelly and inserted into the vagina. Using high-frequency sound waves and their returning echoes, the thickness of the endometrium can be measured with the ultrasound machine on a screen that resembles a television. If the endometrium is less than 5 mm thick, the postmenopausal bleeding is probably due to a thinning of the endometrial lining (atrophy), and endometrial cancer is very unlikely. If the endometrium is thickened it could mean cancer or benign thickening of the lining due to too much oestrogen. Further tests are necessary when the endometrial line is thicker than 5 mm.
- Biopsy: For a biopsy, the doctor uses a thin plastic or metal instrument, which can be inserted through the vagina and cervix into the uterine cavity without anaesthesia. A small amount of endometrial tissue is removed, which - after appropriate processing and staining - is examined under a microscope by a pathologist.
- Hysteroscopy and D&C (dilatation and curettage): This investigation can be done under general anaesthesia in a hospital or under local anaesthesia as an office procedure. The gynaecologist injects a local analgesic in or around the cervix, which is similar to the local injection given by a dentist before filling or removing a tooth. Once the cervix is pain free, the doctor inserts an endoscope (hysteroscope) into the uterus through which the inside of the uterus can be assessed. A hysteroscope is a long lens that helps the doctor to see into the uterine cavity. The advantage of the hysteroscopic examination is that the entire cavity can be inspected and any abnormally appearing tissue can be targeted and sampled under visual control. A curette (a small spoon-shaped instrument) may be placed through the dilated cervix and the lining of the uterus removed with a scraping action (curettage). Endometrial tissue can also be obtained by applying suction through a slender tube (called suction curettage). The removed tissue is examined histologically for evidence of cancer. Hysteroscopy with target biopsy or curettage has replaced the conventional D&C, since the latter is carried out blindly and may miss cancerous changes of the endometrium.
If endometrial cancer is detected on histological examination, additional tests are performed to find out whether the disease has spread from the uterus to other parts of the body. These procedures include blood tests and a chest X-ray. For some patients, special X-rays are needed. For example, computerised tomography (also called CT or CAT scan) is used to take a series of X-rays of various sections of the abdomen.
How is it treated?
A number of factors are considered to determine the best treatment for cancer of the uterus. Among these factors are the stage of the disease (how far the cancer has spread from the endometrium into the muscle of the uterus and to other adjacent or distant organs), the growth rate of the cancer, and the age and general health of the woman. Surgery, radiotherapy, hormone therapy, or chemotherapy may be used alone or in combination to treat uterine cancer.
In its early stage, cancer of the uterus is treated with surgery. The uterus and cervix are removed (total abdominal hysterectomy), as well as the Fallopian tubes and ovaries (salpingo-oophorectomy). While in the past some doctors recommend radiation therapy before surgery to shrink the cancer, primary surgery is the treatment of choice. This allows proper staging of the disease, and the decision, whether postoperative radiotherapy is necessary will depend on the histological examination of the removed tissue.
Some cases with early endometrial cancer are cured by surgery alone, while more advanced cases require postoperative external radiation therapy. Treatment with internal radiation, called intracavitary radiation, is often added. Radiation therapy uses high-energy rays to kill cancer cells. The aim of the radiotherapy is to reduce the chances of recurrence of local disease (cancer that reappears in the lower abdomen or upper vagina).
If the cancer has spread extensively or has recurred after treatment, a female hormone (progesterone) or chemotherapy may be recommended.
In hormone therapy, female hormones are used to stop the growth of cancer cells. Chemotherapy is the use of drugs (chemicals) to treat cancer. Often, a combination of these methods is used.
It is rarely possible to limit the effects of cancer treatment so that only cancer cells are destroyed. Normal, healthy cells may be damaged at the same time. That is why the treatment often causes side-effects.
Side-effects of treatment
Hysterectomy is a major operation. After the operation, the hospital stay usually lasts about four days. For several days after surgery, patients may have problems emptying their bladder and bowels. The lower abdomen usually is sore after the operation, but this improves as time goes by. Normal activities, including sexual intercourse, can be resumed in four to eight weeks.
Women who have their uterus removed, no longer have menstrual periods. When the ovaries are not removed (hysterectomy performed for indications other than uterine cancer), women do not have symptoms of menopause (change of life) because their ovaries still produce hormones. If the ovaries are removed or damaged by radiation therapy, menopause occurs. Hot flashes or other symptoms of menopause caused by treatment may be more severe than those following natural menopause. However, a variety of medications are available to alleviate these symptoms.
Sexual desire and the ability to have intercourse usually are not affected by hysterectomy. Several women have an emotionally difficult time after a hysterectomy. They may have feelings of deep emotional loss.
Radiation therapy destroys the ability of cells to grow and divide. Both normal and cancer cells are affected, but most normal cells are able to recover quickly. Patients usually receive external radiation therapy as an outpatient. Treatments are given five days a week for several weeks. This schedule helps to protect healthy tissues by spreading out the total dose of radiation.
During radiation therapy, patients may notice a number of side-effects, which usually disappear when treatment is completed. Patients may have skin reactions (redness or dryness) in the area being treated, and they may be unusually tired. Some have diarrhoea and frequent and uncomfortable urination. Treatment can also cause dryness, itching, and burning in the vagina. Intercourse may be painful, and some women are advised not to have intercourse at this time. Most women can resume sexual activity within a few weeks after treatment ends.
Hormones occur naturally in the body. Their purpose is to regulate the growth of specific cells or organs. In cancer treatment, hormones are sometimes used to stop the growth of cancer cells. Hormones travel through the bloodstream to all parts of the body, affecting cancer cells far from the original tumour. Hormone therapy usually causes few side-effects.
Anticancer drugs also travel through the bloodstream to almost every area of the body. Drugs used to treat cancer can be given in different ways. Some are given by mouth and others are injected into a muscle, a vein, or an artery. Chemotherapy is most often given in cycles; a treatment period, followed by a recovery period, then another treatment period, and so on.
Depending on the drugs that the doctor orders, the patient may need to stay in the hospital for a few days so that the effects of the drugs can be watched. Often, the patient receives treatment as an outpatient at the hospital, at a clinic, at the doctor's office, or at home.
The side-effects of chemotherapy depend on the drugs given and the individual response of the patient. Chemotherapy commonly affects hair cells, blood-forming cells, and cells lining the digestive tract. As a result, patients may have side-effects such as hair loss, lowered blood counts, nausea, or vomiting. Most side-effects go away during the recovery period or after treatment is over.
Loss of appetite can be a serious problem for patients receiving radiation therapy or chemotherapy. Researchers are learning that patients who eat well are often better able to withstand the side-effects of treatment. Therefore, nutrition is important. Eating well means getting enough calories to prevent weight loss and having enough protein in the diet to build and repair skin, hair, muscles, and organs. Many patients find that eating several small meals throughout the day is easier than eating three large meals.
The side-effects that patients have during cancer therapy vary from person to person and may even be different from one treatment to the next in the same patient. Attempts are made to plan treatment to keep problems to a minimum, and fortunately, most side-effects are temporary. Doctors, nurses, and dieticians can explain the side-effects of cancer treatment and suggest ways to deal with them.
Follow-up after treatment
Regular follow-up examinations are very important for any woman who has been treated for cancer of the uterus. The doctor will want to watch the patient closely for several years to be sure that the cancer has not returned. In general, follow-up examinations include a gynaecological examination, a chest X-ray, and laboratory tests.
Living with cancer
When people have cancer, life can change for them and for the people who care about them. These changes in daily life can be difficult to handle. When a woman finds out she has uterine cancer, a number of different and sometimes confusing emotions may appear.
At times, patients and family members may feel depressed, angry, or frightened. At other times, feelings may vary from hope to despair or from courage to fear. Patients usually are better able to cope with their emotions if they can talk openly about their illness and their feelings with family members and friends.
Concerns about the future, as well as about medical tests, treatments, hospital stays, and medical bills, often arise. Talking to doctors, nurses, or other members of the health care team may help to ease fear and confusion. Patients can ask questions about their disease and its treatment and can take an active part in decisions about their medical care. Patients and family members often find it helpful to write down questions for the doctor as they think of them. Taking notes during visits to the doctor also can help patients remember what was said. Patients should ask the doctor to repeat or explain more fully anything that is not clear.
Patients have many important questions to ask about cancer. Their doctor is usually the best person to provide answers. The Hospice Society of South Africa and CANSA (Cancer Association of SA) are two of the well-known organisations that work with cancer patients and their families. One of these organisations is usually represented in a town or district. The contact telephone numbers should be in the local telephone directory.
(Reviewed by Dr Hennie Botha, University of Stellenbosch and Tygerberg Hospital)