Cervical cancer screening: evidence behind the guidelines.

Cervical cancer screening involves a complex process of cytology, human papillomavirus (HPV) testing, colposcopy, and a multitude of algorithms for the identification of preinvasive disease and prevention of invasive disease. High-risk HPV is a prerequisite for the development of almost all types of cervical cancer; therefore, a test for high-risk HPV has become an integral part of new screening strategies. Major changes to screening guidelines in the last decade include initiation of screening at age 21 years, conservative management of young women with abnormal cytology, extended screening intervals for women age ≥30 years, and cessation of screening in low-risk women at age 65 years. This review will focus on the evidence that has led to the current evidence-based guidelines. Evidence regarding primary HPV testing as well as postvaccine-based screening strategies will also be reviewed.