Cervical carcinoma is the second most common cancer in women worldwide and is the third leading cause of cancer-related deaths. In the United States, although the incidence and mortality rates have significantly decreased since the introduction of the Papanicolaou smear (cervical cytology test) as a screening test in 1941, it is still sixth in cancer incidence and tenth in mortality rate for women of African-American and Hispanic descents. The discrepancy in rates worldwide and within the United States is largely due to differences in availability of cervical cancer screening programs.
Squamous cell carcinomas comprise the majority of the cancers of the cervix (~80%) and are the type that has benefitted most from cervical cytology screening. Infection with high-risk types of HPV has been shown to be a necessary but not sufficient cause of cervical cancer. There are 15 high-risk types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73, and 82), with HPV16 as the most common type in squamous cell carcinomas. Carcinogenesis involves progression from intraepithelial and in situ lesions to invasive carcinoma.
Two vaccines against HPV have been approved by the FDA. Gardasil (Merck, Whitehouse Station, NJ) is a quadrivalent vaccine against HPV types 6, 11, 16, and 18, and is approved for females aged 9–26 for prevention of cervical, vaginal and vulvar cancer caused by HPV types 16 and 18, and for females and males aged 9–26 for the prevention of anal cancer and genital warts caused by HPV types 6 and 11.