Amanda Pritchard, NHS England’s chief executive, announced an ambition this week to eliminate cervical cancer in England by 2040. The country is not unique in its pledge to banish cervical cancer to the realms of historical diseases, the first time this would be achieved for any cancer.
The World Health Organization (WHO) has a target of eliminating cervical cancer globally by the end of the century, which would mean the prevention of the deaths of millions of women. The moonshot has been propelled by two facts: cervical cancer affects a huge number of women (more than 600,000 cases and 340,000 deaths globally in 2020) and yet nearly all these cases are preventable.
“Normally I’m very sceptical about this kind of thing, but the outlook is actually quite positive,” said Prof Sarah Hawkes, a global public health researcher at University College London. “Cervical cancer is much higher up priority lists than we’d expected it to be.”
Cervical cancer is unusual in that more than 95% of cases are linked to human papillomavirus (HPV), the most common viral infection of the reproductive tract. Most sexually active women and men will be infected at some point in their lives and the infection itself is normally harmless and cleared by the immune system. But if it lingers on in cervical cells, it can trigger mutations that set these cells on a path to becoming first abnormal and then cancerous.
So when the first HPV vaccine was approved in 2006, global health experts began drawing up a master plan for elimination. “We decided it would be feasible because we had the tools to do it,” said Dr Nathalie Broutet, a consultant in health sciences research based in Geneva, who led the WHO’s cervical cancer programme until last year. “We had the vaccine, we had the screening, we just had to do a calculation: what does elimination mean?”
The WHO settled on a definition of below four cases per 100,000 women each year. To achieve this by the end of the century requires that by 2030, 90% of girls will be vaccinated, 70% of women screened twice by age 45 years, and 90% of women identified with cervical pre-cancer or cancer to be treated.
The WHO strategy set things in motion, putting cervical cancer in the spotlight as a solvable disease. Progress has been rapid. Australia expects to become one of the first countries to achieve the goal in the next 10 years; Nigeria, where 8,000 women died of cervical cancer last year, is vaccinating 7.7 million girls over the next year; Bangladesh and Indonesia have national HPV vaccine programmes.
“We’ve defined it as a ‘must-win’ goal,” said Emily Kobayashi, the head of the HPV vaccine programme at the international vaccine initiative Gavi. “For cervical cancer, 90% of the deaths in the world take place in low- and middle-income countries that Gavi works with. With most of those countries it’s the first or second most common female cancer.”
An initial challenge has been winning the argument, with both parents and institutions, that teenage girls should be vaccinated against a sexually transmitted infection. This hasn’t always gone smoothly. India’s HPV vaccination programme was derailed in 2010 by a communications breakdown following a number of adverse events in a pilot trial (later deemed unrelated to the vaccine) that fuelled fears about encouraging teenage promiscuity and vaccine misinformation.
“A large proportion of the hesitation was the rollout of a vaccine that had the word ‘sex’ in it somewhere,” said Hawkes. “That’s why it’s not generally rolled out as an STI vaccine, it’s a cancer-prevention vaccine. Once you call it an STI vaccine parents say, ‘My little girl doesn’t need that, thank you.’ It was a brilliant case study in how not to roll out a vaccine.”
The Indian pilot was abruptly stopped and the country’s national rollout only recommenced this year. But the unplanned experiment, in which girls ended up receiving either one, two or three doses of the vaccine, helped demonstrate that just one dose of the HPV vaccine provides equal protection against the virus.
Last year guidance changed to recommend a single dose, and this massively lowered the bar for running an effective immunisation programme and effectively doubled supply of the vaccine, which had until recently constrained Gavi’s spending on HPV.
Gavi has committed $600m to HPV vaccine rollouts for 2022-2025 with the aim of giving the vaccine to 86 million girls worldwide.
Meeting the screening target is a far bigger challenge for many countries. “For a vaccine, a school nurse can do it and you only need to see that girl once. For screening adult women [you need] a health system that works,” said Hawkes. HPV tests are expensive, there is less international funding available and there are cultural barriers.
“In many countries, a vaginal examination is taboo,” said Broutet. “The family is involved. Women need the permissions of the husband or mother-in-law.”
The ramp up of screening has been more modest, with only 65% of countries offering national cervical cancer screening services, and this could ultimately delay the end-goal of elimination, which will take much longer with vaccination alone.
“Yes there are challenges, but it’s a golden opportunity,” said Broutet. “We know it’s feasible. We need to make it happen.”
