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HPV vaccine cuts cervical cancer by nearly 90% — UK population registry study

The human papillomavirus (HPV) vaccine is cutting cervical cancer incidence by nearly 90%, the first real-world data from the UK, published in The Lancet, show. The HPV immunisation programme has almost eliminated cervical cancer in women born in England since Sept 1, 1995, the study found.

Cancer Research UK described the findings as “historic”, and said it showed the vaccine was saving lives.

Nearly all cervical cancers are caused by viruses, and the hope is vaccination could almost eliminate the disease. The researchers said the success meant those who were vaccinated may need far fewer cervical smear tests too.

BBC reports that cervical cancer is the fourth most common cancer in women around the world, killing more than 300,000 each year. Almost nine out of 10 deaths are in low and middle income countries where there is little access to cervical cancer screening. The hope is vaccination will have an even bigger impact in those countries than wealthier nations, such as the UK.

More than 100 countries have starting using the vaccine as part of World Health Organization plans to get close to eliminating cervical cancer. In the UK, girls are offered the vaccine between the ages of 11 and 13, depending on where they live. The vaccine has also been offered to boys since 2019.

The HPV vaccine can only prevent an infection, it cannot rid the body of the virus once it has been caught. The viruses are so widespread that immunisation has to be aimed at children before they become sexually active.

The study, published in The Lancet, looked at what happened after the vaccine was introduced for girls in England in 2008. Those pupils are now adults in their 20s. The study showed a reduction in both pre-cancerous growths and an 87% reduction in cervical cancer.

“The impact has been huge,” said Prof Peter Sasieni, one of the researchers at King’s College London.

The reductions were less dramatic when older teenagers were immunised as part of a catch-up campaign. This is because fewer older teenagers decided to have the jab and they may already have been sexually active.

Overall, the study estimated the HPV programme has prevented about 450 cancers and 17,200 pre-cancers.

Sasieni said that was “just the tip of the iceberg” because those vaccinated were still young to be getting cancer, so the numbers would only grow with time.

At the moment, women are invited for a smear test every three to five years to screen for cervical cancer.

But Sasieni said there “definitely” needed to be a rethink after these results. “It should be a wake-up call to policy-makers. Women will read this and think, ‘Why should I go for screening?’

“I would hope we’d come back with a new screening programme, two to three times a lifetime, and continue screening women who have not been vaccinated.”

This is not the final say on the HPV vaccination, adds the BBC report. There are still questions about how long protection lasts and whether there needs to be a mid-life booster.

There are also more than 100 types of human papillomavirus. The UK started using a vaccine that protected against two of them and is about to introduce one that protects against nine viruses, including the main causes of genital warts.

The cancer-causing versions lead to dangerous changes to the DNA of infected cells that transform them into cancer. This can happen in any infected tissue. The viruses can be spread through vaginal, oral and anal sex, so are also linked to anus, penis and some head and neck cancers. However, 99% of cervical cancers are caused by human papillomaviruses.

Dr Vanessa Saliba, a consultant epidemiologist for the UK Health Security Agency, said the findings were “remarkable” and showed the vaccine “saves lives by dramatically reducing cervical cancer rates among women”.

Michelle Mitchell, the chief executive at Cancer Research UK, said: “It’s a historic moment to see the first study showing that the HPV vaccine has and will continue to protect thousands of women from developing cervical cancer.”

BBC article – HPV vaccine cutting cervical cancer by nearly 90% (Open access)
https://www.bbc.com/news/health-59148620

Study details

The effects of the national HPV vaccination programme in England, UK, on cervical cancer and grade 3 cervical intraepithelial neoplasia incidence: a register-based observational study

Milena Falcaro, Alejandra Castañon, Busani Ndlela, Marta Checchi,
Kate Soldan, Jamie Lopez-Bernal, Lucy Elliss-Brookes, Prof Peter Sasieni

Published in The Lancet on 3 November 2021

Summary

Background
Human papillomavirus (HPV) immunisation with a bivalent vaccine (Cervarix) was introduced in England, UK, in Sept 1, 2008: routine vaccination was offered to girls aged 12–13 years with a catch-up programme for females aged 14–18 years in 2008–10. We quantified the early effect of this immunisation programme on cervical cancer and cervical carcinoma in situ, namely grade 3 cervical intraepithelial neoplasia (CIN3), registrations.

Methods
In this observational study, we used an extension of the age-period-cohort Poisson model to estimate the relative risk of cervical cancer in three vaccinated cohorts compared with earlier cohorts that were not eligible for HPV vaccination. Data from a population-based cancer registry were extracted on Jan 26, 2021, and were assessed for diagnoses of cervical cancer and CIN3 from Jan 1, 2006 to June 30, 2019 in women aged 20–64 years and who were a resident in England. We used three vaccinated cohorts to account for differences in the school year in which the vaccine was offered and its national coverage. Adjustment for confounding was made using information on changes in cervical screening policy and historical events that affected cervical cancer incidence. Results were compared across models with different adjustments for confounders.

Findings
We used data from a total of 13·7 million-years of follow-up of women aged 20 years to younger than 30 years. The estimated relative reduction in cervical cancer rates by age at vaccine offer were 34% (95% CI 25–41) for age 16–18 years (school year 12–13), 62% (52–71) for age 14–16 years (school year 10–11), and 87% (72–94) for age 12–13 years (school year 8), compared with the reference unvaccinated cohort. The corresponding risk reductions for CIN3 were 39% (95% CI 36–41) for those offered at age 16–18 years, 75% (72–77) for age 14–16 years, and 97% (96–98) for age 12–13 years. These results remained similar across models. We estimated that by June 30, 2019 there had been 448 (339–556) fewer than expected cervical cancers and 17 235 (15 919–18 552) fewer than expected cases of CIN3 in vaccinated cohorts in England.

Interpretation
We observed a substantial reduction in cervical cancer and incidence of CIN3 in young women after the introduction of the HPV immunisation programme in England, especially in individuals who were offered the vaccine at age 12–13 years. The HPV immunisation programme has successfully almost eliminated cervical cancer in women born since Sept 1, 1995.

 

BBC article – HPV vaccine cutting cervical cancer by nearly 90% (Open access)

 

The Lancet article – The effects of the national HPV vaccination programme in England, UK, on cervical cancer and grade 3 cervical intraepithelial neoplasia incidence: a register-based observational study (Open access)

 

See more from MedicalBrief archives:

 

HPV vaccine significantly lowers infection rates in teen girls — CDC study

 

HPV vaccine critical to protect against cancer in poorer countries

 

HPV vaccine shows success in gay and bisexual men — HYPER2 study

 

 

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