Human papillomaviruses (HPV) are very common sexually transmitted viruses of which there are many types. HPV is sometimes referred to as the ‘common cold’ of sexual activity; prior to the advent of HPV vaccination, it was estimated that around 80% of people were infected with at least one type of HPV at some point in their lifetime, usually without ever knowing.
In the majority of cases, HPV will be cleared by the body’s immune system within one or two years, with no harmful effects or treatment required. But persistent infection with some types of HPV can cause serious illness including cervical, anal, oropharyngeal, vaginal, vulvar and penile cancers.
Notably, HPV is responsible for virtually all cases of cervical cancer. Worldwide, cervical cancer remains one of the gravest threats to women’s lives. Globally, one woman dies of cervical cancer every two minutes and 85% of cervical cancers occur in less developed regions.
The good news is cervical cancer is one of the most preventable and treatable forms of cancer. Well-established cervical screening programs have already had a dramatic impact on cervical cancer incidence in high-income countries. Similarly, high coverage HPV vaccination programs are having a dramatic impact rates of the cervical abnormalities that precede cancer in younger women.
Cervical cancer prevention in Australia
Australia is likely to be the first country to eliminate cervical cancer as a public health issue – and so it provides an example of what might be possible in other countries. Australia has been at the forefront of cervical cancer prevention for decades. It was the first country to introduce a national publicly-funded HPV vaccination program in 2007, with an extended catch-up in the early years of the program for females aged 12 up to 26 years. In 2013, Australia introduced vaccination for adolescent males, and in 2018 the next-generation HPV vaccine was introduced, which protects against seven cancer-causing HPV types that are associated with around 90% of cervical cancers.
Australia has also had a comprehensive organised screening program since 1991, which halved cervical cancer incidence rates in women aged 25+ years within around 10-15 years. Prompted by established evidence on primary HPV-based screening, and additionally the impact of vaccination, in December 2017, Australia transitioned to 5-yearly HPV-based cervical cancer screening.
Dramatic impact of HPV vaccination and screening
The combined impact of these prevention interventions will be dramatic. Recent modelling by my team at Cancer Council NSW predicts cervical cancer rates could drop to less than 6 in 100,000 in Australia by 2022 – meaning that cervical cancer will soon be classified as a rare cancer in Australia.
Rates will continue to drop to below 4 in 100,000 and the associated mortality will fall below 1 per 100,000 women by around 2035. Although the threshold for eliminating cervical cancer as a public health issue has not yet been set by the WHO, these findings indicate that even at very low thresholds, Australia is set to eliminate cervical cancer in the next 20 years. Other high-income countries are likely to follow within the next few decades.
Towards global elimination of cervical cancer
Recognising the enormous potential to reduce and prevent suffering from cervical cancer worldwide, in 2018 WHO Director-General, Dr Tedros Adhanom Ghebreyesus made a global call for action towards the elimination of cervical cancer as a public health issue.
“Our challenge is to ensure that all girls globally are vaccinated against HPV and that every woman over 30 is screened and treated for pre-cancerous lesions. To achieve that, we need innovative technologies and strategies.” – Dr Tedros Adhanon Ghebreyesus
New research from our team shows it is feasible to achieve global elimination of cervical cancer as a public health problem if we act now. High priority must be given to scaling up to high coverage HPV vaccination in less developed settings, and to ensure all women have access to HPV-based cervical screening.
We found that if we scale up both HPV vaccination and HPV-based screening rapidly enough, we could potentially prevent up to 13.4 million cervical cancer cases by 2069. And, we could see cervical cancer rates decline below the potential elimination threshold, of less than 4 cases per 100,000 people, across most countries by the end of the century.
We have the tools available – HPV vaccines and HPV screening tests. Now is the time to commit to global scaleup for both interventions, to ensure that all girls and woman around the world have access to these innovations, and to ensure that cervical cancer elimination becomes a reality.