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What cervical screening is appropriate for women who have been vaccinated against high risk HPV? A simulation study
Author(s) -
Landy Rebecca,
Windridge Peter,
Gillman Matthew S.,
Sasieni Peter D.
Publication year - 2017
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.31094
Subject(s) - medicine , vaccination , cervical screening , vaccine efficacy , benchmarking , confidence interval , cervical cancer screening , cervical cancer , gynecology , immunology , cancer , business , marketing
Women vaccinated against HPV16/18 are approaching the age for cervical screening; however, an updated screening algorithm has not been agreed. We use a microsimulation model calibrated to real published data to determine the appropriate screening intensity for vaccinated women. Natural histories in the absence of vaccination were simulated for 300,000 women using 10,000 sets of transition probabilities. Vaccination with ( i ) 100% efficacy against HPV16/18, ( ii ) 15% cross‐protection, ( iii ) 22% cross‐protection, ( iv ) waning vaccine efficacy and ( v ) 100% efficacy against HPV16/18/31/33/45/52/58 was added, as were a range of screening scenarios appropriate to the UK. To benchmark cost‐benefits of screening for vaccinated women, we evaluated the proportion of cancers prevented per additional screen (incremental benefit) of current cytology and likely HPV screening scenarios in unvaccinated women. Slightly more cancers are prevented through vaccination with no screening (70.3%, 95% CR: 65.1–75.5) than realistic compliance to the current UK screening programme in the absence of vaccination (64.3%, 95% CR: 61.3–66.8). In unvaccinated women, when switching to HPV primary testing, there is no loss in effectiveness when doubling the screening interval. Benchmarking supports screening scenarios with incremental benefits of ≥2.0%, and rejects scenarios with incremental benefits ≤0.9%. In HPV16/18‐vaccinated women, the incremental benefit of offering a third lifetime screen was at most 3.3% (95% CR: 2.2–4.5), with an incremental benefit of 1.3% (−0.3–2.8) for a fourth screen. For HPV16/18/31/33/45/52/58‐vaccinated women, two lifetime screens are supported. It is important to know women's vaccination status; in these simulations, HPV16/18‐vaccinated women require three lifetime screens, HPV16/18/31/33/45/52/58‐vaccinated women require two lifetime screens, yet unvaccinated women require seven lifetime screens.