A study in Australia, one of the first countries to introduce the HPV (human papilloma virus) vaccination for treating cervical cancer, has shown a drop in high-grade cervical abnormalities – changes to the cells in the neck of the womb that can be the precursor to cancer.
The nationwide vaccination programs are likely to cut the numbers who get the disease.
While it will take many years to find out whether vaccination programmes definitely reduce the numbers of cervical cancers in the population, Australian scientists were able to analyse the results from their screening programme to find out whether there has been any drop in the number of young women with abnormal cell changes that are the precursor of cancer.
Publishing in the Lancet medical journal, they report that the proportion of girls aged 17 and younger with high-grade abnormalities fell by almost half, from 0.80% to 0.42%.
But there was no drop in the numbers of women with cervical abnormalities who were older than 17. This is unsurprising since the vaccine is known to be most effective if given to girls before they become sexually active.
That finding, say the authors, “reinforces the appropriateness of the targeting of prophylactic HPV vaccines to pre-adolescent girls”.
Michael Quinn, professor of gynaecology and gynaecologic oncology at the University of Melbourne, said: “The study is the first anywhere in the world to show falling rates of high-grade change in very young women.
“Although this is likely to be due to the effects of the vaccination programme, further analysis of information linking women’s smear history to their vaccination history will be needed to prove that the fall is entirely due to vaccination rather than other factors.”