Invasive cervical cancer accounts for 2.3 percent of all cancers that afflict women in the United States. About 13,500 cases of invasive carcinoma of the cervix are diagnosed in the United States each year, while there are at least 50,000 new cases of a pre-invasive cancer—known as carcinoma in situ—where the cancer cells are confined to the surface skin of the cervix.
But since 1940, there has been a steady decrease in the incidence of carcinoma of the cervix because most women with no symptoms are screened with cervical and vaginal Pap smears. The probability at birth that a white woman will eventually develop cervical cancer dropped from 1.1 percent in 1975 to 0.7 percent in 1985. Similarly, for African-American women the probability dropped from 2.3 percent in 1975 to 1.6 percent in 1985.
Types Over 90 percent of cervical carcinomas start in the surface cells lining the cervix and are called squamous cell carcinoma. About 5 to 9 percent start in glandular tissue (adenocarcinoma). Adenocarcinomas are more difficult to diagnose, but they are treated the same way as squamous cell carcinomas and the survival rate, stage for stage, is similar.
