In 2020, the World Health Organization (WHO) launched a strategy to accelerate the elimination of cervical cancer. In 2018, this disease killed 312,000 women worldwide (including around 1,000 in France), for a number of new cases estimated at 570,000 (3,000 in France). Deaths that are all the more regrettable as they are preventable.
“Vaccination against the human papillomavirus is one of the pillars of this WHO eradication strategy”, notes Jean-Baptiste Méric, director of the public health and care division of the National Cancer Institute (INCa). The main cause of this cancer, in fact, is a persistent infection with a virus that is transmitted by sexual route, the human papillomavirus or HPV. When this virus settles permanently in the cervix, it can cause precancerous lesions which, in rare cases, progress to cancer, generally ten to fifteen years after the persistent infection.
A first vaccine targeting HPV (Cervarix, GSK laboratory) appeared in 2007: it acts against types 16 and 18 of the human papillomavirus, responsible for 70% to 80% of cervical cancers. Another vaccine is now available (Gardasil, Sanofi Pasteur MSD laboratory): it is active against four genotypes (6, 11, 16 and 18), and a new version will target 9 genotypes.
Until then, the evidence for the impact of this vaccination was incomplete. “We had predicted that it would take ten years to observe an effect on cervical cancer, given the time between infection and their appearance”, explains Jean-Baptiste Méric.
This gap has just been filled by a British study published in the journal The Lancet, November 3. The authors reviewed data from UK cancer registries between January 2006 and June 2019, including 7 female cohorts, aged 20 to 64 at the end of the study. Results: over the follow-up period, 28,000 cervical cancers and 300,000 precancerous lesions, or non-invasive cervical carcinomas (CIN3), were diagnosed. In the vaccinated cohorts, there were 450 fewer cervical cancers and 17,200 fewer CIN3 than in the unvaccinated cohorts. That is, a drop in cervical cancer rates of 87% in women vaccinated between 12 and 13 years old, 62% in those vaccinated between 14 and 16 years old, and 34% in those vaccinated between 16 and 18 years old. For CIN3 levels, the reductions were 97%, 75% and 39%, respectively.
Major public health problem
“This is an important study because it confirms, with a solid methodology, the trends already observed in Sweden, Finland and the United States among young girls vaccinated before the first sexual intercourse”, relieves Jean-Baptiste Méric. The measured impact is even slightly greater than the expected effect. “It probably reflects a collective immunity effect. “
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