Cervical screening in HPV-vaccinated populations.

Cervical screening with cytology has been the basis for substantial reductions in cervical cancer incidence and mortality in most high-income countries over the last few decades. More recently, there have been two key, parallel developments which have prompted a major re-consideration of cervical screening. The first is the emergence of evidence on the improved sensitivity of human papillomavirus (HPV) DNA testing compared to cytology, and the second is the large-scale deployment of prophylactic vaccination against HPV. A key challenge to be overcome before HPV screening could be introduced into national cervical screening programs was the specificity of an infection, for detection of precancerous lesions. This has been done in three ways: (1) by considering the appropriate age for starting HPV screening (30 years in unvaccinated populations and 25 years in populations with mature vaccination programs and high vaccine uptake) and the appropriate screening interval; (2) via development of clinical HPV tests, which are (by design) not as sensitive to low viral loads; and (3) by introducing effective triaging for HPV-positive women, which further risk-stratifies women before referral for diagnostic evaluation. This review discusses these major developments and describes how the benefits of HPV screening are being optimized in both unvaccinated and vaccinated populations.