Molecular Markers for Early Detection of Cervical Neoplasia

Viral Exanthems and Herpesvirus Branch, Division of Viral and Rickettsial Diseases, National Center forInfectious Diseases, Centers for Disease Control and Prevention, Public Health Service, US Department of Healthand Human Services, Atlanta, GA, USA1. IntroductionIn the United States, cervical cancer screening pro-grams based on exfoliated cervical cytology (Papsmears) have signicantly reduced the incidence of in-vasive cervical cancer. As a result of this success,current cervical cancer screening programs in the USare not directed at invasive disease, but at detection ofthe precursors of carcinoma, referred to as dysplasias,squamous intraepithelial lesions (SIL) or cervical in-traepithelial neoplasias (CIN). The progressive histo-logicandcytologicchangesthatoccurduringthemulti-step process of cervical carcinogenesis can be dividedinto multiple stages, early lesions known as CIN 1 orLSIL and high grade lesions known as CIN 2, 3 orHSIL. The natural history of these cervical cancer pre-cursor lesions is difcult to study because they are usu-ally biopsied or otherwise treated as soon as detected.However, it is clear that CIN 1 and 2 lesions are morelikelytoregressthantoprogresstoinvasivedisease[37,69]. While the risk of progression is greatest for CIN 3lesions, not all of these lesions progress and regressionis recognizedto occurin a signicantbut variablenum-ber of cases [69]. Because of the slow rate of diseaseprogression, targeting early detection at CIN 3 lesionsis an effective strategy to avoid invasive cancer and at