Cervical cancer incidence rates by birth cohort against the backdrop of human papillomavirus vaccination in the United States.

Abstract

Previous cervical cancer incidence trend analyses primarily used period-based approaches, limiting assessment of generational risk shifts against the backdrop of human papillomavirus (HPV) vaccination. Using U.S. Cancer Statistics data and age-period-cohort modeling, we estimated fitted incidence rates at ages 30-31 across birth cohorts (1917-1919 to 1999-2001), adjusted for period deviation. Incidence rates decreased by 1.9% per birth year (95%CI, -1.8% to -2.1%) up to 1951-1953 cohorts, then decelerated to 0.3% annually (95%CI, -0.4% to -0.2%). Starting with 1987-1989 cohort, incidence rates dropped sharply by 10.5% annually (95%CI, -12.7% to -8.4%). Compared with 1970-1979 cohorts, 1990-1999 cohorts had a 54% lower incidence rate (10.2 vs 4.7 per 100,000; rate ratio = 0.46; 95%CI, 0.42 to 0.50). The markedly lower risk among post-1987-1989 cohorts suggests a future reduction in population-level burden as these cohorts age. The finding also has implications for reinforcing HPV vaccination efforts and informing discussions on raising the screening initiation age.