Cervical Cancer
Risk: Cervical disease occurs in the lower, narrow portion of the uterus (womb), which connects to the vagina. Cancer of the cervix typically develops slowly over a number of years. The normal cells lining the cervix gradually change, first to a precancerous condition with several names, cervical intraepithelial neoplasia (CIN) or squamous intraepithelial lesion (SIL) or dysplasia, and then on to cancer in some cases if left untreated. Cervical cancer may be limited to the cervix in some patients, but it can also spread to surrounding tissues and on to distant sites in advanced cases.
Cervical cancer is the second most common cancer in women worldwide, and is a leading cause of death in many countries. The incidence of cervical cancer has decreased by 70% in the United States since routine screening for cervical cancer using the Pap test (Pap smear) began about 50 years ago. Approximately 13,000 new cases are diagnosed yearly.
In most cases, precancerous disease and cancer of the cervix are associated with an infection with certain strains of human papilloma virus (HPV), a sexually transmitted virus. Women who do not have routine screening are at increased risk of cervical cancer. Other risk factors include having many sexual partners, having first sexual intercourse at a young age, smoking cigarettes, giving birth to many children, and having conditions that weaken the immune system, such as AIDS.
Diagnosis: Early cervical cancer and CIN do not cause symptoms, so routine screening is important to detect changes of the cervix. The Pap test is used for screening, and involves scraping cells from the surface and canal of the cervix to look for abnormal changes under the microscope. In some cases, a second test is performed to look for the presence of HPV. If the Pap test or HPV test is abnormal, colposcopy (viewing the cervix with a magnifying device) with possible biopsies of the cervix (removal of small pieces of tissue) is performed. In some cases, an additional larger cone-shaped biopsy (loop excision or conization) may be required.
Patients who have more advanced cancer may have vaginal discharge or bleeding.
Prevention: The Pap test is important for prevention of cervical cancer because it can detect precancerous changes of the cervix that can be treated before cancer develops. Women should have the Pap test at least once every 3 years, beginning about 3 years after they begin to have sexual intercourse, but no later than age 21. Female soldiers are required to have a Pap test annually.
Since cervical cancer is associated with HPV infection, less exposure to HPV will decrease the risk of infection and possible precancerous changes or cancer of the cervix. Avoiding any genital contact with another individual is most effective. A mutually monogamous relationship with an uninfected partner will also prevent HPV infections. Reducing the number of sexual partners and choosing a partner less likely to be infected may reduce the risk of genital HPV infection. It is unclear whether condoms prevent HPV infection, but condom use has been associated with a lower rate of cervical cancer.
A vaccine that prevents cervical cancer by developing immunity against the strains of HPV that cause up to 70% of cases of cervical cancer is due to be released in the summer of 2006. The vaccine is effective in people who have not been infected by HPV previously. The ideal age to administer the vaccine has not yet been determined.
Treatment: Treatment of precancerous lesions depends on how severe the changes are. Mild changes often return to normal without treatment over a number of months. More severe changes are most often treated by removal of the abnormal tissue using loop excision or conization, and in some cases, hysterectomy.
Cervical cancer is treated based on how far the cancer has spread. It can be treated by simple hysterectomy in very early cases. A more extensive hysterectomy that includes tissue surrounding the cervix and the upper portion of the vagina, combined with removal of lymph nodes, can be used for disease of the cervix only or when there is spread to the upper vagina. Chemoradiation (radiation combined with intravenous chemotherapy) is sometimes used as an alternate form of therapy at this stage. More advanced disease requires the use of chemoradiation.
Prevention: The Pap test is important for prevention of cervical cancer because it can detect precancerous changes of the cervix that can be treated before cancer develops. Women should have the Pap test at least once every 3 years, beginning about 3 years after they begin to have sexual intercourse, but no later than age 21. Female soldiers are required to have a Pap test annually.
Since cervical cancer is associated with HPV infection, less exposure to HPV will decrease the risk of infection and possible precancerous changes or cancer of the cervix. Avoiding any genital contact with another individual is most effective. A mutually monogamous relationship with an uninfected partner will also prevent HPV infections. Reducing the number of sexual partners and choosing a partner less likely to be infected may reduce the risk of genital HPV infection. It is unclear whether condoms prevent HPV infection, but condom use has been associated with a lower rate of cervical cancer.
HPV infection can occur in both male and female genital areas that are covered or protected by a latex condom, as well as in areas that are not covered. While the effect of condoms in preventing HPV infection is unknown, condom use has been associated with a lower rate of cervical cancer, an HPV-associated disease. A vaccine that prevents cervical cancer by developing immunity against the strains of HPV that cause up to 70% of cases of cervical cancer is due to be released in the summer of 2006. The vaccine is effective in people who have not been infected by HPV previously. The ideal age to administer the vaccine has not yet been determined.