Cervical Cancer

The cervix is the lower part of the uterus, or womb, of females. It connects the uterus to the vagina, with the part closest to the uterus called the endocervix and the part closest to the vagina called the ectocervix. The junction between the endocervix and ectocervix is called the transition zone because the cell type changes from cuboidal glandular cells to flat, squamous cells. This transition zone is important because most cervical cancers arise in this area. Because there are two different cell types in the cervix, the two major forms of cervical cancer are squamous cell carcinoma and adenocarcinoma of the glandular tissue. Squamous cell carcinomas make up about 80 to 90 percent of all cervical cancers, while the remaining 10 to 20 percent is comprised of adenocarcinomas.

Addressing worldwide disparities in access to healthcare will be an important part of efforts to conquer cervical cancer.

The process by which cervical cancer develops involves several stages from precancerous changes to cancer. The precancerous changes are often referred to as cervical intraepithelial neoplasia (CIN) or squamous intraepithelial lesion (SIL) because they are confined to the epithelial, or outermost, layer of cells. The gradual precancerous changes that occur in the cells of the cervix caused by human papillomavirus (HPV) can be detected by a Pap test, which is a test where the doctor samples cells from the cervix to look for precancerous changes. If the gynecologist or pathologist notes precancerous changes in the patient's Pap smear, more frequent Pap smears may be recommended. In higher-risk patients, further examination of the cervix through a colposcope may also be indicated. In patients who are shown to have precancerous lesions on Pap tests, further testing for the DNA of the HPV may also be indicated. This is because patients with low-grade lesions and acute infection with HPV are at higher risk of developing cancer than those who test negative for the virus.

Because Pap tests are very sensitive and relatively cheap to perform and because there are effective interventions for patients who have positive Pap smears, Pap tests are considered to be highly effective [Page 368]screening tests for cervical cancer. In fact, it has been shown that over 90 percent of all cervical cancers can be detected by Pap smears.

The American Cancer Society has issued guidelines recommending periodic Pap tests for females. It is recommended that all women begin getting Pap smears either three years after their first vaginal intercourse or by the age of 21 at the latest. Periodic testing should be performed every one to two years until the age of 30. For women over the age of 30 who have had three consecutive normal Pap tests, testing can be performed once every two to three years. Women with other risk factors should be tested annually. Women over the age of 70 with three or more normal Pap tests or those who have undergone a total hysterectomy with complete removal of the cervix may cease cervical screening. Although Pap tests are highly effective, it is estimated that about 33 percent of women in the United States do not receive them on a regular basis for a number of reasons.

...