HPV Vaccination and the Risk of Invasive Cervical Cancer
- Study type
- Observational study
- Design
- Population-based cohort study using Swedish national population and health registers (open population)
- Sample size
- 1,672,983 girls and women
- Source
- N Engl J Med · 2020
In plain words
This research looked at the records of more than 1.6 million girls and women aged 10 to 30 in Sweden. The risk of cervical cancer was clearly lower in those who had received the HPV vaccine than in those who had not. The drop was greatest in those vaccinated before the age of 17. These results show that HPV vaccination, especially at younger ages, can play an important part in preventing cervical cancer.
Key results
Treatment arms and regimens
Received quadrivalent human papillomavirus (HPV) vaccine. Dose details in the full text of the paper.
Did not receive HPV vaccine. Dose details in the full text of the paper.
Source of the regimen details: Abstract of the paper (vaccine dose and schedule are not stated in the abstract)
Doses are given for the information of specialists, as in this study’s protocol, and are not a prescription. Every drug must be prescribed by the treating physician for the individual patient.
Study population
Girls and women aged 10 to 30 years living in Sweden, followed from 2006 to 2017. Participants were assessed for cervical cancer up to their 31st birthday.
Endpoints
Association between HPV vaccination and the risk of invasive cervical cancer, adjusted for age at follow-up, calendar year, county of residence and parental characteristics (including education, household income, mother's country of birth and maternal disease history).
Safety and side effects
The abstract reports no information on vaccine adverse events.
Clinical significance and place in guidelines
This population study provides direct evidence that quadrivalent HPV vaccination is associated with a reduced risk of invasive cervical cancer (not just high-grade lesions) at population level, with a greater effect when vaccination occurred before age 17. The abstract alone is not enough to state its place in guidelines; the status of guideline recommendations should be checked separately.
Limitations
This is an observational, register-based study and the authors' conclusion rests on "association", not proof of causation. Although several covariates were adjusted for, residual confounding is possible. Follow-up extended only to age 31 and the findings apply to Swedish women aged 10 to 30 years. The confidence interval for the group vaccinated before age 17 is relatively wide (0.00–0.34).
This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.