Chapter 20: Issues in planning cervical cancer screening in the era of HPV vaccination.

Human Papillomavirus (HPV) vaccines will likely have an impact as a preventive strategy for cervical cancer. Screening for precancerous lesions cannot be discontinued because vaccination will not protect against HPV types not included in the first generation of vaccines. Moreover, protection for the target types, 16 and 18, which are responsible for most cases of cervical precancerous lesions and cancer, and 6 and 11, which are responsible for a substantial proportion of low-grade lesions, cannot be expected to be absolute, and the likely implementation of HPV vaccination in young women will not impact older groups initially. Cervical cancer control programs will need to be re-evaluated because the addition of HPV vaccination will make the existing approach of high-frequency screening by cytology too costly and inefficient for most public health budgets. Simply making cytology screening less frequent may not be a viable strategy in light of potential problems that may plague cytology performance in conditions of low lesion prevalence. HPV testing has the performance characteristics that would make it an ideal primary screening test in such conditions. Cytology should be reserved for triage of HPV-positive cases because it is more likely to perform with sufficient accuracy in high-prevalence conditions. Another advantage of using HPV testing as a primary screening tool is the opportunity to create infection registries that can link test results from the same women over time, thus allowing an efficient and low-cost strategy to monitor long-term protection among vaccinated women.