We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Impact of cervical screening by human papillomavirus genotype: Population-based estimations.
- Authors
Wang, Jiangrong; Elfström, K. Miriam; Lagheden, Camilla; Eklund, Carina; Sundström, Karin; Sparén, Pär; Dillner, Joakim
- Abstract
Background: Cervical screening programs use testing for human papillomavirus (HPV) genotypes. Different HPV types differ greatly in prevalence and oncogenicity. We estimated the impact of cervical screening and follow-up for each HPV type. Methods and findings: For each type of HPV, we calculated the number of women needed to screen (NNS) and number of women needing follow-up (NNF) to detect or prevent one cervical cancer case, using the following individual level input data (i) screening and cancer data for all women aged 25 to 80 years, resident in Sweden during 2004 to 2011 (N = 3,568,938); (ii) HPV type-specific prevalences and screening histories among women with cervical cancer in Sweden in 2002 to 2011(N = 4,254); (iii) HPV 16/18/other HPV prevalences in the population-based HPV screening program (N = 656,607); and (iv) exact HPV genotyping in a population-based cohort (n = 12,527). Historical screening attendance was associated with a 72% reduction of cervical cancer incidence caused by HPV16 (71.6%, 95% confidence interval (CI) [69.1%, 73.9%]) and a 54% reduction of cancer caused by HPV18 (53.8%, 95% CI [40.6%, 63.1%]). One case of HPV16-caused cervical cancer could be prevented for every 5,527 women attending screening (number needed to screen, NNS). Prevention of one case of HPV16-caused cervical cancer required follow-up of 147 HPV16–positive women (number needed to follow-up, NNF). The NNS and NNF were up to 40 to 500 times higher for HPV types commonly screened for with lower oncogenic potential (HPV35,39,51,56,59,66,68). For women below 30 years of age, NNS and NNF for HPV16 were 4,747 and 289, respectively, but >220,000 and >16,000 for HPV35,39,51,56,59,66,68. All estimates were either age-standarized or age-stratified. The primary limitation of our study is that NNS is dependent on the HPV prevalence that can differ between populations and over time. However, it can readily be recalculated in other settings and monitored when HPV type-specific prevalence changes. Other limitations include that in some age groups, there was little data and extrapolations had to be made. Finally, there were very few cervical cancer cases associated with certain HPV types in young age group. Conclusions: In this study, we observed that the impact of cervical cancer screening varies depending on the HPV type screened for. Estimating and monitoring the impact of screening by HPV type can facilitate the design of effective and efficient HPV-based cervical screening programs. Trial registration: ClinicalTrials.gov with numbers NCT00479375, NCT01511328. Joakim Dillner and colleagues estimate the impact of cervical screening and follow-up for preventing and detecting one case of cervical cancer caused by each HPV type. Author summary: Why was this study done?: Cervical screening programs now use testing for human papillomavirus (HPV). Different HPV types differ greatly in prevalence and oncogenicity, therefore screening for and further management of certain HPV types may cause excessive false positives and resource consumption. How cervical screening program may be impacted by screening for different HPV types has not been sufficiently studied. What did the researchers do and find?: We integrated the Swedish nationwide data of HPV genotype and cervical screening history among cervical cancer cases as well as the general population and calculated "number needed to screen" and "number needing follow-up" for preventing and detecting one case of cervical cancer caused by each HPV type. The impact of cervical screening was very different from different HPV types: prevention or detection of one cervical cancer case caused by HPV16 involved much fewer women in screening and required much fewer being followed up, as compared to types with lower oncogenic potential, such as HPV35, 39, 51, 56, 59, 66, 68. In young women, screening and follow-up of HPV35, 39, 51, 56, 59, 66, 68 would require unreasonably large efforts per prevented or detected case, whereas in older women, screening and follow-up of these HPV types appeared reasonable. HPV18-related cervical cancer was inadequately prevented in cytology-based screening. What do these findings mean?: Cervical screening programs may consider selecting which HPV types to screen for or follow-up, depending on women's age. HPV vaccination is changing the HPV type-specific prevalence in the population, thus monitoring the impact of screening by HPV type can facilitate the design of effective and efficient HPV-based cervical screening programs. The major limitation is that HPV prevalences are changing over time, necessitating updated calculations of the impact.
- Subjects
SWEDEN; HUMAN papillomavirus; GENITAL warts; MEDICAL screening; EARLY detection of cancer; HUMAN papillomavirus vaccines; CERVICAL cancer
- Publication
PLoS Medicine, 2023, Vol 20, Issue 10, p1
- ISSN
1549-1277
- Publication type
Article
- DOI
10.1371/journal.pmed.1004304