A team of researchers from Queen Mary University of London (UK) have reported that women may only need three cervical screens in their lifetime if they have been given the HPV vaccine. The findings were recently published in the International Journal of Cancer.
In order to determine an appropriate screening intensity for vaccinated women, the group of researchers utilized a microsimulation model calibrated to real published data. They then went onto simulate natural histories in the absence of vaccination for 300,000 women utilizing 10,000 sets of transition probabilities.
To benchmark cost-benefits of screening for vaccinated women, the researchers evaluated the proportion of cancers prevented per additional screen (incremental benefit) of current cytology and likely HPV screening scenarios in unvaccinated women.
The team discovered in these simulations that 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.
Overall the authors state that: “Our analyses clearly demonstrate that many fewer lifetime screens are necessary for vaccinated women to have the same level of protection against cervical cancer as is currently provided by 3- and 5-yearly cytology screening in unvaccinated women…. This [research] emphasizes the importance of recording vaccination status, and linking this information to the screening programs call–recall database.”
The results are based on how the HPV vaccine and the improved cervical screening program will work best together. The new program termed HPV primary testing is set to be introduced in England by December 2019. It means that cervical samples are tested for HPV but only checked for abnormal cells if the virus is found. The current test checks for abnormalities first, which is less efficient.
Peter Sasieni, Cancer Research UK’s screening expert and lead author based at QMUL, commented: “The NHS should benefit from the investment that it’s made by introducing the vaccination program. These women are far less likely to develop cervical cancer so they don’t need such stringent routine checking as those at a higher risk. This decision would free up resources for where they are needed most. The change in the screening system is a unique opportunity to reassess how often women are invited for cervical screens during their lifetimes.”
Sources: Landy R, Windridge P, Gillman MS, Sasieni PD What cervical screening is appropriate for women who have been vaccinated against high risk HPV? a simulation study doi: 10.1002/ijc.31094 Int. J. Cancer (2017); Science Daily press release