What are cervical, ovarian, and uterine cancers?

Causes and Symptoms

Although people commonly talk about cancer as a single disease, it actually includes more than one hundred different diseases. These diseases do appear to have a common element to them. All cancer cells divide without obeying the normal control mechanisms. These abnormal cells have altered deoxyribonucleic acid (DNA) that causes them to divide and form other abnormal cells, which again divide and eventually form a neoplasm, or tumor.

If the neoplasm has the potential to leave its original site and invade other tissues, it is called malignant. If the tumor stays in one place, it is benign. One major difference between these tumors is that
malignant cells seem to have lost the cellular glue that holds them to one another. Therefore, they can metastasize, leaving the tumor and infiltrating nearby tissues. Metastatic cells can also travel to distant sites via the blood or lymph systems.

Medical scientists do not know exactly what causes a cell to become cancerous. In fact, it is likely that several different factors in some combination cause cancer. Genetic, viral, hormonal, immunological, toxic, and physical factors may all play a role. Whatever the cause, cancer is a common disease, resulting in one out of five deaths in the United States. Tumors of the reproductive tract occur in relatively high rates in women. Cervical cancer accounts for 6 percent, ovarian cancer 5 percent, and cancer of the lining of the uterus (endometrial cancer) 7 percent of all cancers in women.

Cervical cancer is most frequently found in women who are between forty and forty-nine years of age, but the incidence has been steadily increasing in younger women. Several factors appear to be involved in initiating this cancer: young age at first intercourse; number of sexual partners (as well as the number of the partner’s partners); infection with sexually transmitted diseases such as herpes simplex type 2 and human papillomavirus; and cigarette smoking. Since most patients do not experience symptoms, regular checkups are necessary. The Pap (Papanicolaou) testing performed in a physician’s office will detect the presence of cervical cancer. In this procedure, the physician obtains a sample of the cervix by swabbing the area, then places the cells on a microscope slide for examination.

Ovarian cancer accounts for more deaths than any other cancer of the female reproductive system. While the cause of ovarian cancer is unknown, the risk is greatest for women who have not had children. Researchers recently discovered that the genes BRCA1 and BRCA2,
usually associated with hereditary forms of breast cancer, are also connected to an increased rate of ovarian cancer. About 5 to 10 percent of ovarian cancers appear to have a strong hereditary association, particularly in patients who develop the cancer at a young age. Its incidence is slightly decreased in women who use oral contraceptives for many years. Ovarian tumors generally affect women over fifty years of age.

There are two major types of ovarian cancer: epithelial and germ cell neoplasms. About 90 percent of ovarian cancers are epithelial and develop on the surface of the ovary. These tumors often are bulky and involve both ovaries. Germ cell tumors are derived from the eggs within the ovary and, if malignant, tend to be highly aggressive. Malignant germ cell neoplasms tend to occur in women under the age of thirty.

Ovarian cancer is generally considered a silent disease, as the signs and symptoms are vague and often ignored. Abdominal pain is the most obvious symptom, followed by abdominal swelling. Some patients also report gastrointestinal disorders such as changes in bowel habits. Abnormal vaginal bleeding may occur, but like the other symptoms this is not specific for the disease. Diagnosis is made using imaging techniques such as ultrasound, computed tomography (CT) scanning, and magnetic resonance imaging (MRI). The presence and identification of the BRCA1 and BRCA2 genes also allows a woman to aggressively monitor her health, even though her predisposition for ovarian cancer cannot be changed.

Uterine cancer, also known as
endometrial cancer, most frequently affects women between the ages of fifty and sixty-five. Like most cancers, the cause of endometrial cancer is not clear. Nevertheless, a relatively high level of estrogens has been identified as a risk factor. For example, obese women, women who have an early onset of their first period (menarche), and women who never became pregnant tend to have high
estrogen levels for longer durations than those without these conditions. Medical scientists believe not only that it is estrogens that are important but also that the other ovarian hormone, progesterone, must be lower than normal for the cancer to develop. Therefore, progesterone appears to have a protective effect in endometrial cancer. Detection of endometrial cancer is accomplished by having a physician take a small tissue sample (biopsy) from the lining of the uterus. The sample can be examined under the microscope to determine if the
cells are cancerous.

Treatment and Therapy

A variety of treatments are available for patients with cancers of the reproductive tract: surgical removal of the organ, hormonal therapy, chemotherapy, or radiation therapy.

The treatment of cervical cancer depends on the size and location of the tumor and whether the cells are benign or malignant. If the patient is no longer capable of or interested in childbearing, then she may choose to have her uterus, including the cervix, removed in the procedure known as
hysterectomy. The physician may also use a laser, cryotherapy (use of a cold instrument), or electrocautery (use of a hot instrument) to destroy the tumor without removing the uterus. Malignant tumors may require a total hysterectomy and removal of associated lymph nodes, which can trap metastatic cells. This surgery may be followed by radiation or chemotherapy if there is a possibility that all cancer cells have not been removed.

Cervical cancer diagnosed in a pregnant patient can complicate the treatment. Fortunately, only about 1 percent of cervical cancers are found in pregnant women. If the cancer is restricted to the cervix (that is, it has not metastasized), treatment is usually delayed until after childbirth. It is interesting to note that a normal vaginal delivery may occur without harming the mother or the infant. Malignant cervical cancer must be treated in a similar way as in nonpregnant women. If the cancer is found in the first trimester, a hysterectomy or radiation therapy or both is used to help eradicate the malignancy. Obviously, these approaches terminate the pregnancy. During the second trimester, the uterus must be emptied of the fetus and placenta, followed by radiation therapy or removal of the affected reproductive organs. In the third trimester, the physician will typically try to delay treatment until he or she believes that the fetus has developed sufficiently to stay alive when delivered by cesarean section. A vaginal delivery is not recommended, as it has been shown to lower the cure rate of
malignant cervical cancer. Treatment after delivery consists of surgery, radiation therapy, and chemotherapy.

The prognosis in patients who have elected surgical removal of the tumor is a five-year survival rate of up to 90 percent. Cure rates for patients undergoing radiation therapy are between 75 and 90 percent. Chemotherapeutic agents have not had as much effect, as they significantly reduce only 25 percent of tumors. It is important to note that the best outcomes are achieved with early diagnosis.

Ovarian cancers are treated with a similar approach. Surgery may involve the removal of the ovaries, uterine tubes, and uterus, as well as associated lymph nodes depending upon the extent of malignancy. Radiation and chemotherapy are usually employed but oftentimes are not effective. The drug taxol is a relatively new agent which shows some promise in treating ovarian cancers. This drug was isolated from the bark of the yew tree and shows some specificity for ovarian tumors. Taxol prevents cell division in ovarian tumors, slowing the progression of the disease.

The outcome for ovarian cancer is usually not as good as for cervical and endometrial cancers, since the disease is usually in an advanced stage by the time that it is diagnosed. The overall survival rate without evidence of recurrence in patients with epithelial ovarian cancers is between 15 and 45 percent. The more uncommon germ cell ovarian cancers have a much more variable
prognosis. With early diagnosis, aggressive surgery, and the use of newer chemotherapeutic agents, the long-term survival rate for all ovarian cancer patients approaches 70 percent.

Surgery is often the treatment of choice for
endometrial cancer. As with cervical cancer, however, treatment depends upon the extent of the disease and the patient’s wishes relative to reproductive capabilities and family planning. A hysterectomy—removal of the uterine tubes, ovaries, and surrounding lymph nodes—is usually indicated. Chemotherapy and radiation therapy are occasionally utilized as adjunctive therapy, as is progesterone. Progesterone (medroxyprogesterone or hydroxyprogesterone) may benefit patients with advanced disease, as it seems to cause a decrease in tumor size and regression of metastases. In fact, progesterone therapy in patients with advanced or recurrent endometrial cancer leads to regression in about 40 percent of cases. Progesterone therapy also has produced regression in tumors that have metastasized to the lungs, vagina, and chest cavity.

The outcome of
endometrial cancer is influenced by the aggressiveness of the tumor, the age of the woman (older women tend to have a poorer prognosis), and the stage at which the cancer was detected. Almost two-thirds of all patients live without evidence of disease for five or more years after treatment. Unfortunately, 28 percent die within five years. For cancer identified and treated early, almost 90 percent of patients are alive five years after treatment.

Perspective and Prospects

Even though medical science has advanced the ability to detect and treat cancers much earlier, many lives are still lost to cancer each year. The Centers for Disease Control and Prevention reports that among women in the United States in 2009, 12,357 were diagnosed with cervical cancer and 3,909 died of the disease; 20,460 were diagnosed with ovarian cancer and 14,436 died of the disease; and 44,192 were diagnosed with uterine and 7,713 died of the disease. According to the World Health Organization, cervical cancer was the seventh most deadly cancer worldwide in 2008, accounting for 275,000 deaths. Therefore, as with most diseases, prevention may be a significant way to reduce one’s chances of getting cancer, as well as of reducing the effects of cancer itself.

The National Institutes of Health and the American Cancer Society have made several suggestions which can be followed to reduce the risk of cancer. The dietary guidelines include reducing fat intake to less than 30 percent of total calories, eating more high-fiber foods such as whole-grain breads and cereals, and eating more fruits and vegetables in general, and in particular those high in vitamins A, C, and E.

Scheduling regular checkups with a health care provider may increase the likelihood of detecting cervical, ovarian, and uterine cancers early, even if no symptoms are present. Pelvic examinations should be performed every three years for women under the age of forty and yearly thereafter. Pap testing for cervical cancer should be undertaken yearly from the time that a woman becomes sexually active. Some physicians will take an endometrial tissue biopsy from women at high risk and at the time of the menopause.

Some data suggest that modifying lifestyle may help reduce the incidence of cervical cancer. The cervix is exposed to a variety of factors during intercourse, including infections and physical trauma. Having multiple sexual partners increases the risk of sexually transmitted diseases which may predispose the cervix to cancer. This factor is compounded by the fact that infectious agents and other carcinogens can be transmitted from one individual to another. Therefore, theoretically the cervix can be exposed to carcinogens from a partner’s sexual partners. Regular intercourse begun in the early teens also predisposes one to cervical cancer, as the tissue of the cervix may be more vulnerable at puberty. Barrier methods of contraception, mainly the condom, reduce the risk of developing cervical cancer by reducing the exposure of the cervix to potential carcinogens. Smoking increases the risk of cervical cancer, perhaps because carcinogens in tobacco enter the blood, which in turn has access to the cervix. Thus, such lifestyle changes as safer sexual practices, quitting smoking, and dietary changes would be beneficial to someone wanting to reduce the chance of having cervical cancer.

Women who are twenty or more pounds over ideal body weight are twice as likely to develop endometrial cancer, and the risk increases with increased body fat. Some estrogens are produced in fat tissue, and this additional estrogen may play a role in the development of endometrial cancer. Therefore, reduction of excess body fat through diet and exercise may be important for a woman who wishes to reduce her chances of developing uterine cancer.

In May 2013, investigators from the Cancer Genome Atlas Research Network reported the results of their comprehensive genomic analysis of close to four hundred endometrial tumors. Their findings, published in the journal Nature, suggest that molecular characteristics can help determine the type of endometrial cancer and possibly yield insights into effective treatment strategies. The investigators also found four new tumor subtypes and identified similarities between endometrial cancer and other types of cancers.

Also in 2013, Dr. Devansu Tewari of Southern California Permanente Medical Group presented the results of a long-term study he authored on the effectiveness of using intraperitoneal chemotherapy to treat ovarian cancer. The study demonstrated that intraperitoneal chemotherapy, in which the patient's stomach area is bathed in chemotherapeutic agents, significantly increased survival rates for patients with advanced ovarian cancer. Patients who received intraperitoneal treatment were 17 percent more likely to survive longer than patients who received conventional intravenous therapy.

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