Population-based surveillance for cervical cancer precursors in three central cancer registries, United States 2009

Abstract

The USA has a well-established network of central cancer registries (CCRs) that collect data using standardized definitions and protocols to provide population-based estimates of cancer incidence. The addition of cervical cancer precursors in select CCR operations would facilitate future studies measuring the population-level impact of human papillomavirus (HPV) vaccine. To assess the feasibility of collecting data on cervical cancer precursors, we conducted a multi-site surveillance study in three state-wide CCRs, to obtain annual case counts and compare rates of precursor lesions to those for invasive cervical cancer. We developed standardized methods for case identification, data collection and transmission, training and quality assurance, while allowing for registry-specific strategies to accomplish surveillance objectives. We then conducted population-based surveillance for precancerous cervical lesions in three states using the protocols. We identified 5,718 cases of cervical cancer precursors during 2009. Age-adjusted incidence of cervical cancer precursors was 77 (Kentucky), 60 (Michigan), and 54 (Louisiana) per 100,000 women. Highest rates were observed in those aged 20-29 years: 274 (Kentucky), 202 (Michigan), and 196 (Louisiana) per 100,000. The variable with the most missing data was race/ethnicity, which was missing for 13 % of cases in Kentucky, 18 % in Michigan, and 1 % in Louisiana. Overall rates of cervical cancer precursors were over sixfold higher than invasive cervical cancer rates [rate ratios: 8.6 (Kentucky), 8.3 (Michigan), and 6.2 (Louisiana)]. Incorporating surveillance of cervical cancer precursors using existing CCR infrastructure is feasible and results in collection of population-based incidence data. Standardized collection of these data in high-quality registry systems will be useful in future activities monitoring the impact of HPV vaccination across states. As a result of this study, ongoing surveillance of these lesions has now been conducted in four CCRs since 2010.