Can the world eliminate cervical cancer?
Cervical cancer is preventable by vaccination and treatable if caught early, yet globally it causes over 300,000 deaths per year, primarily due to inequities in healthcare access.
There was a time when a diagnosis of cervical cancer was a death sentence. Now, with effective tools for prevention and treatment, cervical cancer is set to be the first ever cancer eliminated, according to a landmark World Health Organization (WHO) goal to bring global levels down to four per 100,000 women over the next century.
Launched in 2020, the WHO Global Strategy to Accelerate the Elimination of Cervical Cancer as a Public Health Problem may be ambitious, but most experts are firm that it is achievable.
Fundamentally, unlike many other cancers, cervical cancer is preventable through vaccination as well as screening; and, if found early enough, it is largely treatable.
In some parts of the world, progress has been swift. England has since 2008 administered the human papillomavirus (HPV) vaccine, which protects against types of HPV that cause cervical cancer, to girls aged 12-13, leading to an 87% reduction in cervical cancer cases when they reach their 20s, compared to the unvaccinated population.
As in many high-income countries (HICs) that have implemented similar HPV vaccination programmes, in the UK data shows that in 2016-2018, there were just 2,626 cases of cervical cancer in England and 3,197 in the UK—down by 25% since the early 1990s. Mortality, too, has decreased by 75% since the early 1970s.
But HICs comprise only 16% of the world's population, and elimination in low- and middle-income countries (LMICs) presents a very different set of challenges. In 2021 in India, 3% of women aged 25-64 were screened for HPV, compared with 70% in England.
This stark difference in screening coverage illustrates how managing social determinants of health, including poverty, economic instability and cultural factors, as well as provision of healthcare and education, are key to successful and scalable cervical cancer screening and HPV vaccination programmes.
Understanding global health inequities
Cervical cancer is the fourth most commonly found cancer in women worldwide, accounting for 604,000 new diagnoses in 2020. In 2018, over 300,000 women died from cervical cancer globally, with nearly 90% of the deaths occurring in LMICs.
There are massive inequalities in terms of HPV vaccinations and screening uptake. Even in high-income countries, there are inequalities between different communities.
Dr Nino Berdzuli is director of the Division of Country Health Programmes (CHP) at the WHO, championing the organisation’s global strategy to eliminate cervical cancer as a public health problem. As an obstetrician and gynaecologist, Berdzuli has witnessed first-hand the fear and devastation that cervical cancer wreaks on the lives of women. However, she firmly believes that it can be confined to history with strategic use of the tools currently available.
But, Berdzuli stresses, tackling the drivers of global health inequities is key. "There are massive inequalities in terms of HPV vaccinations and screening uptake," she says. "Even in HICs, there are inequalities between different communities. We need to understand these inequities in early detection and timely treatment within countries. Even wealthier countries with conventionally good health services can still have poor cancer outcomes."
The three pillars of the elimination strategy
Vaccination for HPV types 16 and 18, which account for nearly 70% of cervical cancer cases, was licensed in 2006. By 2019, HPV vaccines had been introduced into national immunisation programmes in more than 100 countries.
If the 90-70-90 target is achieved, modelling projects that the median cervical cancer incidence rate will fall by 42% by 2045, and by 97% by 2120, averting more than 74 million new cases and over 62 million deaths by 2120.
Vaccination of girls aged 12-13 is the first of the pillars that support the elimination goal, followed by screening for precancerous lesions, and, finally, treatment. So impactful are HPV vaccination and cervical cancer screening that they feature as WHO 'best buys'—highly cost-effective interventions designed to combat non-communicable diseases. Other best buys include increasing tobacco and alcohol taxes and reducing salt content in food products.
The WHO’s ‘90-70-90 target’ for 2030 envisages administering 90% of girls globally with the HPV vaccine by age 15; screening 70% of women with a high-performance test by age 35 and a second time by age 45; and ensuring treatment for 90% of women diagnosed with cervical cancer.
If the 90-70-90 target is achieved, then modelling projects that the median cervical cancer incidence rate will fall by 42% by 2045, and by 97% by 2120, averting more than 74 million new cases and over 62 million deaths by 2120.
As an early adopter of HPV vaccination and cervical cancer screening, Australia is well on track to achieve elimination at the national level, potentially by 2030. Professor Megan Smith, lead researcher of The Daffodil Centre’s cervical cancer and HPV group, a joint venture between Cancer Council NSW and the University of Sydney, says that Australia’s screening programme, which began in 1991, and vaccination drive have nearly halved the incidence and mortality rates for cervical cancer. At seven per 100,000 women and just 222 deaths in 2022, or 1.5 per 100,000 women, Australia’s incidence and mortality rates for cervical cancer are among the lowest in the world.
Because precancerous cervical cell changes usually have no symptoms, screening for any potentially harmful changes is extremely important, explains Smith. "Screening is critical to catching these abnormalities before they develop into cancer.”
An estimated 940 Australian women are diagnosed with cervical cancer each year. While this is encouraging for a country of 25 million people, the task now, according to Professor Smith, is ensuring equity—making elimination of cervical cancer a reality for all Australian women.
Rates of cervical cancer among Aboriginal and Torres Strait Islander women, for example, are as high as 20 per 100,000. “As well as maintaining high participation in our vaccination programme, it is critical we improve equity in who participates,” Smith says.
She says there is help in the form of a recent policy change that allows women eligible for screening to choose between self-sampling or sample collection by a clinician.
Taking vaccines and screening services to the people
In LMICs, shortage of funds and distances often hinder access to HPV vaccination and cervical cancer screening. By surface area, India is the seventh largest country in the world, and access to healthcare can be challenging. The country bears a fifth of the world’s cervical cancer burden, with an incidence rate of 18 per 100,000 women. HPV vaccination is not included in the national vaccination schedule despite the introduction of a national cancer screening programme in 2016.
We are waiting for the indigenous manufacture of the HPV test because right now we import it and that's expensive. Once the cost comes down, coverage through screening will increase
"In urban women, breast cancer is the number one cancer in incidence, while in the rural and semi-urban areas there are more new cases of cervical cancer," says Raghunadharao Digumarti, Professor and head of medical oncology at GSL Medical College in Rajahmundry.
“[Rural women] cannot come to an urban area for a test because the majority are agricultural workers earning a daily wage; if they travel to a city for screening and miss work, then they don't get paid.”
Given the low coverage of HPV vaccination and cervical cancer screening in the country, the services must be localised and timed with crop holidays to help improve access and uptake among rural populations, Digumarti says. “It can often take a day or more to reach the urban area, but if [the vaccination and screening service] is offered within their community, they're ready to take it up," says Digumarti.
He says the rollout of India's covid-19 vaccination campaign holds lessons, with the vaccine administered door-to-door. "Vaccination and screening need to be brought where girls and their mothers live."
In a further learning from the pandemic, HPV vaccines that are manufactured locally help lower costs and improve access, Digumarti says. In September 2022, the Serum Institute of India announced the launch of the country’s first cervical cancer vaccine, which will offer a low-cost alternative to the other vaccines in the market.
Likewise, says Dr Leela Digumarti, director at Natco Pharma and a gynaecological oncologist at Kim's Icon Hospital in Visakhapatnam, "we are waiting for the indigenous manufacture of the HPV test because right now we import it and that's expensive. Once the cost comes down, coverage through screening will increase."
Tackling cultural barriers and disinformation
With 260 million inhabitants, Nigeria, like India, has more than its share of logistical challenges in rolling out an HPV vaccination and cervical cancer screening programme at scale. Rates of cervical cancer hover at about 18 per 100,000 women, yet there is no national screening or vaccination programme. However, it is cultural barriers that are among the hardest to overcome.
Dr Zainab Shinkafi-Bagudu is first lady of Kebbi State and a consultant paediatrician with a focus on cancer. She also sits on the board of the Union for International Cancer Control (UICC) and is chair of the First Ladies Against Cancer (FLAC) Nigeria, which aims to increase awareness about cancer and facilitate access to screening and treatment services across the country.
Shinkafi-Bagudu says challenges to cervical cancer elimination in Nigeria include raising awareness of the value of vaccination and screening, and facilitating public health initiatives to help overcome resistance to vaccination.
She highlights the need to not only educate people about the benefits of HPV vaccination but also counteract myths that the vaccine is harmful to young girls, especially as cervical cancer is the second leading cause of female cancer mortality in Nigeria, behind breast cancer. "The issue of vaccinating young girls can be very culturally sensitive, with some believing these interventions are designed to sterilise or are a form of contraception," Shinkafi-Bagudu says.
What’s more, in Nigeria the school-based immunisation programmes that work so well in HICs fail to make an impact since only 60% of primary school-aged children regularly attend school. FLAC and other cervical cancer advocates in Nigeria are awaiting approval of a proposal to GAVI, the Vaccine Alliance, for supply of vaccines at US$5 each. Initially these would be rolled out, via the national immunisation programme, to girls attending school and, later, to out-of-school girls, too.
The vast inequalities in access to HPV vaccination and cervical cancer screening globally reinforce the fact that healthcare does not function in a vacuum. Medical research has succeeded in creating the technology and tools, but these cannot achieve elimination on their own.
Berdzuli at the WHO says adapting a global goal at a local level requires policymakers to be sensitive to the needs of individual communities.
She uses the example of Denmark to illustrate her point. An HPV vaccination programme for 12-year-old girls that started in 2009 had achieved a vaccine uptake of over 90%. However, in 2013, negative media coverage suggested there were serious side effects from the vaccine and the uptake plunged. After a concerted effort by health authorities, uptake rebounded, but it is estimated that 26,000 fewer girls received the vaccine than if uptake had not declined.
"It's important to understand the concerns among different communities using behavioural and cultural insights so we can tailor our communication programmes to meet the concerns of these communities," Berdzuli says.