Study Confirms Vaccine Could Prevent More Cases Of Cervical Cancers Than Previously Expected

Main Category: Cervical Cancer / HPV Vaccine
Article Date: 15 Jul 2010 - 1:00 PDT

email to a friend   printer friendly   opinions  

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, according to a study published in the British Journal of Cancer. 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.

The UK introduced HPV vaccination for secondary school age girls in 2008 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 NHS 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."

Cervical screening remains the best way for adult women to reduce their risk of cervical cancer, as they won't have received the vaccine when they were younger. Also, because current vaccines don't protect against all HPV types that cause cancer, screening remains necessary for vaccinated as well as unvaccinated women, to prevent cervical cancer caused by other types of HPV infection.

Notes

1. Data taken from R Howell-Jones et al (2010), "Multi-site study of HPV type-specific prevalence in women with cervical cancer, intraepithelial neoplasia and normal cytology, in England", The British Journal of Cancer, vol 104, July 14.

2. HPV has about 100 different types, about 40 of which can infect the genitals. The vast majority of these sexually transmitted HPV infections cause no ill-effects. However, some types, such as HPV 6 and 11, can lead to genital warts. Other types, such as HPV 16 and 18 can cause cervical cancer in women. Other studies have shown these two HPV types cause around 70% of cervical cancers.

3. To ensure maximum benefit and protection from vaccination, it should be administered before the onset of sexual activity. Since September 2008 there has been a national programme, delivered largely through secondary schools, to vaccinate girls aged 12-13 against human papillomavirus (HPV).There is also a three-year catch up campaign that will offer the HPV vaccine (also known as the cervical cancer jab) to 13-18 year old girls.

4. During the first year of the vaccination programme at least 80% of 12-13 year old girls in England completed a course of HPV vaccination. More information can be found here.

5. Cervical cancer is the eleventh most common cancer in women in the UK and the third most common gynaecological cancer after uterus (womb) and ovary. There are around 2,860 new cases of cervical cancer diagnosed in the UK each year, that is around 55 women every week.

6. Cervical cancer accounts for 1 in ten cancers diagnosed in women worldwide.

7. The British Journal of Cancer is owned by Cancer Research UK. Its mission is to encourage communication of the very best cancer research from laboratories and clinics in all countries. Broad coverage, its editorial independence and consistent high standards have made BJC one of the world's premier general cancer journals.

8. For more information about HPV, cervical cancer and genital warts, check the HPA's Human Papillomavirus page.

Source:
Health Protection Agency

• Additional
• References
• Citations