Clinical Question

Is the human papillomavirus (HPV) vaccine associated with a lower risk of invasive cervical cancer?

Bottom Line

HPV vaccination is associated with a significant reduction in the likelihood of invasive cervical cancer (adjusted incidence rate ratio [IRR] = 0.37; 95% CI, 0.21 to 0.57). The magnitude of this reduction was greater in women who were vaccinated before 17 years of age (adjusted IRR = 0.12; 95% CI, 0.00 to 0.34). (Level of Evidence = 2b)

Synopsis

There are limited data regarding whether HPV vaccination prevents invasive cervical cancer. This Swedish study used data from a national health registry of more than 1.6 million girls and women who were between 10 and 30 years of age from 2006 to 2017. In Sweden, HPV vaccination was offered to girls 13 to 17 years of age starting in 2007, with expansion to younger and older girls in 2012. Cervical cancer screening in Sweden begins at age 23 and is performed at intervals of three to seven years, depending on age. A quadrivalent vaccine (types 6, 11, 16, and 18) was used. The researchers reviewed registries with information about cancer diagnoses and vaccination. A total of 1,145,112 patients did not receive an HPV vaccine, whereas 527,871 received at least one dose during the study period. At baseline, girls who were vaccinated were more likely to have a Swedish-born mother and come from a high-income family. The primary outcome was the IRR for invasive cervical cancer between vaccinated and unvaccinated girls and women, adjusted for age, calendar year of immunization, and parental and residential characteristics. The crude incidence rates were 5.3 per 100,000 person-years for unvaccinated participants and 0.73 per 100,000 person-years for those who had been vaccinated. The fully adjusted IRR was 0.37 (95% CI, 0.21 to 0.57) for invasive cervical cancer. For girls vaccinated before 17 years of age, the IRR was 0.12 (95% CI, 0.00 to 0.34), and for those vaccinated between 17 and 30 years of age, it was 0.47 (95% CI, 0.27 to 0.75).

Study design: Cohort (retrospective)

Funding source: Foundation

Setting: Population-based

Reference: Lei J, Ploner A, Elfström KM, et al. HPV vaccination and the risk of invasive cervical cancer. N Engl J Med. 2020;383(14):1340–1348.

Editor's Note: Dr. Ebell is deputy editor for evidence-based medicine for AFP and cofounder and editor-in-chief of Essential Evidence Plus, published by Wiley-Blackwell.