Navigation

Stages Of Cervical Cancer

Definition

Cervical cancer is a disease in which the cells of the cervix become abnormal and start to grow uncontrollably, forming tumors.

Description

The cervix is the lower part or the neck of the uterus (womb). It connects the uterus to the vagina (birth canal). Cervical cancer generally begins as an abnormality in the cells on the outside of the cervix. The initial changes that occur in the cells are not cancerous and are referred to as "dysplasia." Over a period of time, more changes may occur that make the cells cancerous. They start to grow uncontrollably and invade the deep layers of the cervix. This is referred to as "invasive cancer."

Cervical cancer is a very slow growing cancer. The change in the cells from normal to pre-cancerous to cancerous is very gradual and may take several years to develop. For this reason, routine screening tests for cervical cancer are very important. When detected early, pre-cancers and very early cervical cancers are nearly 100% curable.

In the United States, cervical cancer accounts for 6% of all cancers in women. It usually affects women between the ages of 40 and 55 years. Worldwide, cervical cancer is the second most common cancer among women, with over 400,000 new cases diagnosed each year. The incidence is very high in developing countries. In the last 40 years, there has been a 75% decrease in the number of deaths due to cervical cancer in the United States. The main reason is the use of the "Pap test" as a screening tool. The test identifies the pre-invasive and the early invasive disease stages, which, if treated appropriately, have a cure rate of nearly 100%.

Causes & symptoms

The cause of cervical cancer is not known. However, certain factors are believed to increase one's risk of developing cervical cancer. Engaging in sexual activity at a young age is one such factor. The cells lining the cervix do not fully mature until the age of 18 and, therefore, are more susceptible to cancer causing-agents and viruses.

More than 90% of women with cancer of the cervix are infected with the human papilloma virus (HPV). Hence, HPV infection is the single most important risk factor for cervical cancer. The HPV belongs to a group of 70 viruses that can cause warts (papillomas). HPV usually causes warts in the genital area. The viruses are passed from one person to another during unprotected sex. Having multiple sexual partners increases one's risk of getting this cancer, because the greater the number of sexual partners, the greater is the risk of acquiring HPV infection. Even if a woman has only one sexual partner, but the man has several partners, he is considered a "high-risk male" and can transmit HPV to the woman.

Smoking is considered a risk factor, possibly because smoking causes some abnormal changes in the cells and these cells have a higher likelihood of becoming cancerous.

There has been no direct proof linking the use of oral contraceptives with cervical cancer. Nevertheless, some statistical studies have suggested that long-term use of oral contraceptives may put a woman at a slightly higher risk of developing this cancer.

In its early stages, cervical cancer may have no symptoms. Often, the diagnosis is made during a routine pelvic examination. Some women experience symptoms such as bleeding between periods (irregular vaginal bleeding); post-menopausal vaginal bleeding; vaginal bleeding after intercourse; and vaginal discharge with an unpleasant odor. When the cancer is in an advanced stage and has invaded the tissue surrounding the cervix, a woman may have pain in the pelvic area, and heavy bleeding from the vagina.

Diagnosis

A Pap smear is the best screening test used to detect cancer of the cervix. It is done as a part of a regular pelvic exam. A medical swab or brush is rubbed against the cervix. The tissue sample collected is smeared on a slide and sent to the laboratory for microscopic examination. This test detects cervical abnormalities more than 95% of the time. A negative test means that no abnormalities are present. If a Pap test is positive, an abnormality has been detected in the cell lining the cervix.

Because the Pap test is a screening test, rather than a diagnostic test, the doctor will order a biopsy. The purpose of the biopsy is to check if the abnormality is due to a pre-cancerous change or if cancer is present. During the biopsy, a piece of cervical tissue is removed and examined under a microscope. A cervical biopsy can be performed in several different ways. In a procedure known as colposcopy, the doctor uses a magnifying scope to view the surface of the cervix clearly. If any abnormal areas are seen, the doctor can use a pair of biopsy forceps to remove a small piece of the suspicious area for further testing. An additional procedure, known as endocervical curettage, uses a narrow instrument called curette to scrape off some tissue from the inside of the cervix. The tissue is then sent to the laboratory for examination.

A cone biopsy is sometimes used to remove a cone-shaped piece of tissue from the cervix for microscopic examination. In addition, it can be used to treat many of the pre-cancers and very early cancers. Two methods are most commonly used for performing the cone biopsy. In one method, known as loop electrosurgical excision procedure (LEEP), the tissue is removed by using a wire that is heated by electrical current. In the cold knife cone biopsy, a surgical scalpel is used to remove the tissue.

In addition to the Pap test and the biopsy results, several other tests may be used to determine the stage of the disease after a diagnosis of cervical cancer has been made. A cytoscopy may be ordered to check whether the cancer has spread to the urinary bladder and kidneys. Similarly, a proctoscopy will detect whether the cancer has spread to the rectum, and chest x rays may be ordered to check the lungs. Imaging tests such as computed tomography scans (CT) and magnetic resonance imaging (MRI) will help to identify the spread of the cancer to the nearby lymph nodes or other organs near the cervix.

Treatment

Treatment for cervical cancer depends on the stage of the disease and the extent of its spread. The three standard modes of treatment are surgery, radiation therapy, and chemotherapy.

A radical hysterectomy removes the entire uterus, the ovaries, the upper part of the vagina that is next to the cervix, and the lymph nodes from the pelvic region.

Radiation therapy, which involves the use of high energy x rays to kill cancer cells, can also be used for treating cervical cancer. In external radiation therapy, the rays are focused on the pelvic area from a source that is outside the body. Alternatively, a pellet of radioactive materials may be placed internally, near the tumor. This is called brachytherapy or interstitial radiotherapy. However, radiation therapy to the pelvic region has many effects. It could cause a narrowing of the vagina (vaginal stenosis) that makes intercourse painful. It may also stop the ovaries from releasing eggs and producing the female hormone estrogen. When this happens, it causes premature menopause in young women and they will need estrogen replacement therapy. Many women are treated with both surgery and radiation therapy.

Chemotherapy, or the use of anticancer drugs to kill the cancer cells, is not a common form of treatment for cervical cancer because it is not as effective as other methods. Nevertheless, the effectiveness of combination chemotherapy, (where more than one drug is used to treat the cancer), is being tested in clinical trials.

When the woman is diagnosed with recurrent cervical cancer, an operation known as pelvic exenteration is performed. In this operation, besides the uterus, cervix, and vagina, the urinary bladder, part of the colon, and the rectum are also removed. In such a case, new openings will have to be created for the urine and the feces to pass out of the body. A new vagina may also be surgically created.

Prognosis

When detected in the early invasive stages, approximately 91% of the women survive 5 years or more. The overall 5 year survival rate for cervical cancer, from the time of detection, is 69%.

Prevention

Most cases of cervical cancers can be prevented, since they start with easily detectable pre-cancerous changes. One of the best ways to prevent cervical cancers is by having regular Pap tests. If pre-cancerous changes are detected, appropriate treatment can prevent them from developing into invasive cancers.

Another way to prevent cervical cancers is to avoid the risk factors. Abstaining from sexual relations when one is very young, and using appropriate precautions (condoms) when engaging in sexual activity will help to avoid HPV infections. Quitting smoking will also help to reduce the risk for cervical and many other cancers.

Key Terms

Colposcopy

A diagnostic procedure using a hollow, lighted tube (colposcope) to look inside the cervix and the uterus.

Cone biopsy

Removal of a cone of tissue from the opening of the cervix.

Cytoscopy

A diagnostic procedure using a hollow, lighted tube (cytoscope) to look inside the bladder and the urethra.

Dysplasia

Abnormal cellular changes that may precede cancer.

Loop electrosurgical excision procedure (LEEP)

A medical procedure in which abnormal tissue is cut out using a wire that is heated by electric current.

Pap test

A medical procedure that is used to screen for cervical and other cancers. The test involves the removal of some tissue from the cervix for microscopic examination.

Proctoscopy

A medical procedure using a thin, flexible, hollow, lighted tube to view the rectum clearly.

Further Reading

For Your Information

Books

• Dollinger, Malin. Everyone's Guide to Cancer Therapy. Somerville House Books Limited, 1994.
• Merck Manual of Diagnosis and Therapy,16th ed., edited by Robert Berkow et al. New Jersey: Merck Research Laboratories, 1992.
• Morra, Marion E. Choices. NY: Avon Books, October 1994.
• Murphy, Gerald P. Informed Decisions: The Complete Book of Cancer Diagnosis, Treatment and Recovery. Atlanta: American Cancer Society, 1997.

  Organizations

• American Cancer Society (National Headquarters). 1599 Clifton Road, N.E. Atlanta, Georgia 30329. (800) 227-2345. http://www.cancer.org.
• Cancer Research Institute (National Headquarters). 681, Fifth Avenue, New York, N.Y. 10022. (800) 992-2623. http://www.cancerresearch.org.
• Gynecologic Cancer Foundation. 401 North Michigan Avenue, Chicago, IL 60611. (800) 444-4441. gcf@sba.com.
• National Cancer Institute. 9000 Rockville Pike, Building 31, room 10A16, Bethesda, Maryland, 20892. (800) 422-6237. http://wwwicic.nci.nih.gov.

  Other

• NCI/PDQ Patient Statement, "Cervical Cancer." National Cancer Institute.
• 1998 Cancer facts and figures. American Cancer Society.

Gale Encyclopedia of Medicine. Gale Research, 1999.