HPV vaccines provide hope for major international programmes of primary prevention

Parents of young girls may soon be offered the opportunity to have their daughters immunised against a sexually transmitted virus that is the major cause of cervical cancer, the 4th International Conference on Teenage and Young Adult Cancer Medicine.

Professor Henry Kitchener told the conference, organised by the Teenage Cancer Trust charity, that progress in developing vaccines against the human papillomavirus (HPV) had reached a stage where they were soon to be submitted for licensing. But he warned that it was important there were programmes of education for women and men, particularly parents, about HPV and cervical cancer.

Professor Kitchener, of the Academic Unit of Obstetrics and Gynaecology at the University of Manchester, UK, said: "It is vital that people understand the context in which HPV vaccination is being proposed and that they realise that it is not a treatment for the virus once it has been contracted, or for cervical cancer if the disease has started to develop. Vaccination should not be misconstrued as a green light for sexually permissive behaviour - rather, it is an effective means of preventing HPV infection when young women are most susceptible in their teenage and young adult years.

"The origins of cervical cancer lie in HPV infection of the cervix, a sexually transmitted infection most frequently acquired by women shortly after they start sexual activity. In a minority of women, the HPV infection persists and may result in pre-cancerous changes; these can develop into cancerous changes in these women, particularly if they are unscreened. Testing for HPV infection is becoming talked about more, as is the potential of vaccination. In particular, there are two types of HPV, types 16 and 18, at which vaccine research is being directed. HPV 16 and 18 are thought to be responsible for 70% of cervical cancers worldwide.

"If the current vaccinations that are being developed are approved for use, then they could be used to vaccinate girls at puberty in order to prevent HPV infection. By preventing HPV infection, this could have the effect of preventing the pre-cancerous and cancerous changes that HPV infection can trigger. Women and men need to be more aware of HPV infection and what it may mean. Parents who may be asked to consent to their children being vaccinated need to be aware of these important issues."

There are nearly 500,000 new cases of cervical cancer diagnosed each year worldwide, and every year nearly 274,000 women die from the disease, with about 80% of these deaths occurring in developing countries where there is little or no access to cervical screening programmes.

"HPV vaccination has the potential to make a huge difference to women's lives, particularly in developing countries," said Professor Kitchener. "Cervical cancer is a major killer of women worldwide. It is not only one of the largest causes of death due to cancer, but is also responsible for a great deal of suffering. Tragically, its regions of highest incidence are those in which preventative screening cannot be provided due to lack of resources, and those least well equipped to treat the condition for the same reason.

"In more affluent well-developed countries, cervical screening by means of cytology has become an established strategy for identifying women at risk of developing cervical cancer and has been responsible for a dramatic fall in incidence and death rates. Vaccination programmes will still require some form of screening to be in place either for unvaccinated women or for women who develop an HPV infection despite the vaccination. Falling death rates have also been due to improved forms of treatment for advanced disease, principally in the form of concomitant chemotherapy and radiotherapy."

Professor Kitchener concluded: "HPV vaccines provide hope for major international programmes of primary prevention."