Abstract
PURPOSE: To estimate the population-based incidence of HPV vaccination after childhood cancer. METHODS: Pediatric and young adult cancer survivors identified in the institutional Comprehensive Cancer Center registry were linked to the North Carolina Immunization Registry (NCIR). Initiation and completion of any HPV vaccine was evaluated in survivors born between 1984 and 2002 with an NCIR record by December 2014. Descriptive statistics and Kaplan-Meier estimates of cumulative incidence were stratified by sex and age at eligibility for vaccine. Cox proportional hazards were conducted and stratified by sex. RESULTS: Among 879 (n = 428 female; n = 451 male) study-eligible cancer survivors without prior HPV vaccination (n = 501 < 18 years, n = 378 ≥ 18 years at the time of eligibility), the cumulative incidence of HPV vaccine initiation following cancer therapy was 48.1% among females at 8.2 years and 29.2% among males at 5.0 years after vaccine eligibility among those < 18 years, and 6.2% among females at 8.1 years and 2.0% among males at 4.2 years after vaccine eligibility among those ≥ 18 years. Among those who initiated vaccination, 53% of females and 43% of males completed a 3-dose series. Younger age at cancer diagnosis (≤ 10 and 11-14 years vs. ≥ 15 years) and shorter interval from diagnosis to vaccine eligibility were more likely to initiate vaccination in models adjusted for age at eligibility, race/ethnicity, cancer type, relapse, and transplant. CONCLUSIONS: Despite the benefit of a cancer prevention strategy, cancer survivors are sub-optimally vaccinated against HPV. IMPLICATIONS FOR CANCER SURVIVORS: Immunization registries can help oncologists and primary care providers identify gaps in vaccination and target HPV vaccine delivery in survivors.