Gynaecologists at Amsterdam UMC took the initiative for this study because they are concerned about low vaccination rates. ‘We saw several young women with cervical cancer who had not been vaccinated in recent years,’ explains gynaecologist-oncologist Luc van Lonkhuijzen. ‘I struggle with the idea that maybe their disease could have been prevented. With this study, we want to draw attention to the importance of vaccinating against HPV. It can prevent a lot of misery.’
Infertility due to cancer treatment
The protective effect of vaccination against (the pre-stages of) cervical cancer was previously shown by several large international studies. This study shows for the first time the effect of HPV vaccination among young women in the Netherlands. The researchers analysed the medical records of 135 women under 30 with cervical cancer. Of them, 58 per cent lost their fertility as a result of the necessary treatments. Van Lonkhuijzen: ‘That is obviously very drastic, quite apart from the risk of women dying from cervical cancer. If with a vaccination we can ensure that women are less likely to get cervical cancer, then these treatments and thus infertility would not be necessary at all.’
Vaccination rate must go up
Cervical cancer is usually caused by infection with HPV, a virus that almost everyone contracts once in their lifetime. In most cases, the body clears the virus itself. But sometimes it doesn't. Then, years later, HPV can cause cervical cancer (and cancer of the vagina and labia, penile cancer in men and anus and oral cavity cancer in both).
HPV vaccination has been part of the National Vaccination Programme since 2010, but vaccination coverage lags behind. Among girls born between 1997 and 2010, it stands at 60-70 per cent (RIVM). ‘We must do everything we can to get that rate higher,’ says lead researcher Maaike van der Aa of IKNL. ‘In recent campaigns, young people could still get a vaccine, but a large proportion remains unvaccinated. Our study shows that the majority of cervical cancer cases occur in the unvaccinated group.’
More research needed
Although HPV vaccination significantly reduces the risk of cervical cancer, the study shows that even vaccinated women can get this form of cancer. Van der Aa: ‘In the Netherlands, we have a so-called “bivalent” vaccine, which only protects against HPV types 16 and 18 and not against all high-risk HPV types. More research is needed among the group of vaccinated women with cervical cancer to find out what is going on there. Did they get cancer from a different type of high-risk HPV? Or are there also women who do get that type of cancer despite vaccination against HPV 16 and 18?’
Importance of screening
Because HPV vaccination reduces but does not eliminate the risk of cancer, participation in population screening for cervical cancer remains crucial. Van Lonkhuijzen: ‘That population screening is very easy these days with the HPV self-test. Unfortunately, the participation rate in that screening is also under pressure. Of all women over the age of 30, only about 50 per cent participate.’ Early detection, he says, can prevent drastic treatments and increase the chances of fertility preservation. ‘Apart from the better prognosis, it means a lot to a woman of childbearing age if she can undergo treatment where she can still have children at a later date.’
The study is part of a broader effort to evaluate the effectiveness of HPV vaccination in the Netherlands and raise awareness about prevention. You can find the full results in the online pre-publication.