The cervix is the part of the uterus connected to the upper vagina. It is the structure that dilates during childbirth to allow the baby to traverse the birth canal. There are two major types of cancer that develop from the cervix. Squamous cell cancers arise from the squamous epithelium that covers the visible part of the cervix.
Adenocarcinomas arise from the glandular lining of the endocervical canal.
Squamous cell cancers are unique because there is a well established progression through premalignant changes before a cancer develops. These premalignant changes are easy to detect by a simple screening test called the Pap test. The cause of cervical cancer is unknown. HPV can be transmitted sexually, so there is an association with sexual activity. The strongest association, however, is that women who have been celibate all their lives almost never develop a squamous cell cancer of the cervix.