Vaccine could prevent more cases of cervical cancer

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A study published in the British Journal of Cancer today (Wednesday 14 July 2010) has revealed that scientists at the Health Protection Agency (HPA), the University of Manchester and the Manchester Royal Infirmary have found that the cervical cancer vaccine could prevent more cases of the disease in England than previously thought.

This could potentially reduce the annual number of cases from around 3000 to less than 700.

Cervical cancer is caused by an infection called human papillomavirus (HPV). The study found that 73%-77% of cervical cancer cases were caused by either HPV type 16 or 18, both of which are prevented by the current vaccine used in the UK.

Prior to this study, the available data had suggested 70% of cases were caused by these types. Current vaccines do not protect against all HPV types that cause cervical cancer, but they do protect against these two most common types.

In 2008, The UK introduced HPV vaccinations for secondary school age girls and, as with the introduction of any new vaccine, it is important to monitor and evaluate its impact.

This study, which was funded by the National Cervical Cancer Screening Programme, looked at what types of HPV were present in more than 6000 samples from women of different ages, and with different stages of cervical disease, from normal to cancer in England. These results help to improve the HPA’s estimates of the expected effect of the HPV immunisation programme.

Vaccination against the most common strains of HPV – 16 and 18 – may also give women some protection against other similar HPV types. The study showed how many cancers in England are due to these other HPV types and estimated that cross protection could prevent a further 3-4% of cervical cancers – potentially another 90-120 cases annually.

A substantial proportion of less serious cervical disease is also likely to be prevented by immunisation, meaning that fewer women will be called back for further investigations and treatment following cervical screening.

Dr Kate Soldan, an HPA epidemiologist who worked on the study, said: “This study looked at the different strains of HPV that women have, across England and across all ages and grades of cervical disease.

“We’ve found that, if vaccine uptake is good, the HPV vaccine should prevent the majority of cases of cervical cancer in this country. Because the vaccine is given to teenage girls and cervical cancer affects adult women, it will be some years before we see the actual impact of immunisation, but we do expect to start seeing these effects in coming years, as vaccinated girls become adults.”