The International Agency for Research on Cancer (IARC) estimates that in 2020 more than 600 000 women were diagnosed with cervical cancer worldwide and approximately 340 000 women died from the disease.
Cervical cancer was the fourth most commonly diagnosed cancer type in women, after breast cancer, colorectal cancer, and lung cancer. It was also the fourth most common cause of cancer death in women. Cervical cancer is a major public health problem that affects middle-aged women, particularly in low- and middle-income countries.
Below are answers from IARC experts to questions about cervical cancer.
The vast majority (about 80%) of new cases of cervical cancer occur in lower-resource countries. Cervical cancer is the most commonly diagnosed cancer type and the leading cause of cancer death in many countries, particularly in sub-Saharan Africa. The risk of developing the disease varies markedly between countries and across regions. The highest incidence rates are observed in sub-Saharan African countries such as Eswatini and Malawi, where the rates are more than 10 times those in North America, Australia and New Zealand, and Western Asia (Saudi Arabia). China and India, as emerging economies with large populations, account for about 40% of the global burden of cervical cancer.
Infection with human papillomavirus (HPV) types 16 or 18 is the main cause of cervical cancer. Countries with a high risk of cervical cancer tend to be those where girls do not have access to vaccination against HPV and women are seldom screened for cervical cancer.
Cervical cancer is a great example of a cancer that can be eliminated. With specific public health policies and actions taken by policy-makers at the population level, cervical cancer can go from being one of the most common cancer types in women in many countries to being a rare cancer.
There are two very effective, safe, and affordable public health interventions to prevent cervical cancer: vaccination of pre-adolescent and adolescent girls (ages 9–14 years) against HPV, and regular screening of women starting at the age of 25 or 30 years.
Nearly all cases of cervical cancer are caused by infection with oncogenic HPV types, and the transmission of HPV can be significantly reduced by vaccinating girls before they become sexually active. The vaccine also offers protection from other cancer types caused by HPV, such as anal cancer, vulvar cancer, vaginal cancer, and oropharyngeal (throat) cancer. Adolescent boys can also be vaccinated to protect them against anal cancer, oropharyngeal cancer, and penile cancer. IARC studies have shown that vaccinating both boys and girls can reduce the transmission of HPV infection in the community faster and may lead to faster elimination of these cancer types than vaccinating only girls. However, the priority for countries should be to vaccinate girls first, because the burden of disease is much higher in females and high vaccination coverage (> 80%) of girls reduces HPV transmission to a level at which boys are also protected from the above-mentioned cancer types – a principle called herd protection.
Long-standing infection of the cervix with HPV leads to the development of certain precancerous conditions (dysplasia), which, if left undetected and untreated, may give rise to cervical cancer after 5–10 years. HPV can be detected with very simple tests in which cervical secretions are collected with a swab and tested in a laboratory. Infection with HPV does not by itself mean that a woman will develop cervical cancer. In fact, most HPV-positive women will not develop the disease. However, because of the higher risk, HPV-positive women need to undergo further tests to ensure that they do not have any dysplasia of the cervix.
The HPV vaccine is the most expensive vaccine ever to be introduced into national immunization programmes. Reducing the number of doses needed to confer protection will not only decrease the procurement costs but also lower the administrative expenses and simplify the logistics.
If dysplasia of the cervix is detected, it can be treated with very simple techniques. Special equipment is available (cryotherapy, thermal ablation) to ablate the area of the cervix affected by the condition.
The World Health Organization (WHO) global strategy to accelerate the elimination of cervical cancer as a public health problem was launched in 2020. The strategy calls for at least 90% of girls to be vaccinated against HPV by age 15 years, at least 70% of women to be screened twice with an HPV test by age 45 years, and at least 90% of the precancerous lesions and cancers detected by screening to be appropriately managed. WHO has estimated that if these 90–70–90 targets are met by 2030, then cervical cancer could cease to be a public health problem across the globe by the end of this century.
Implementation of the WHO global strategy to achieve the 90–70–90 triple targets will enable all countries to reach a cervical cancer incidence rate of fewer than 4 cases per 100 000 women. WHO is bringing together various international and national stakeholders to garner support for the initiative, ensure the affordability of HPV vaccination and screening, and build in-country capacity to eliminate this cancer.
IARC scientists are closely involved with the various activities and have been leading some of the expert groups initiated by WHO to develop and implement the global strategy. IARC researchers are at the forefront of evidence synthesis for the forthcoming guidelines on cervical cancer screening and treatment of precancers being developed by WHO, including those related to the implementation and deployment process for cervical screening. IARC is also participating in other initiatives and technical reports, such as developing the WHO Framework for Strengthening and Scaling-up Services for the Management of Invasive Cervical Cancer and WHO technical guidance and specifications for medical devices for the screening and treatment of precancerous lesions for cervical cancer prevention. The newly formed WHO Academy has selected IARC to lead the development of a comprehensive learning programme for various levels of professionals involved in cervical cancer screening.
The WHO initiative places robust surveillance and monitoring systems at its core, and population-based cancer registries play a critical role in reporting the evolution of baseline cervical cancer incidence rates and the impact of interventions over time. However, the level of development of population-based cancer registries in lower-resource settings is suboptimal and requires considerable investment.
IARC is committed to helping to initiate and strengthen population-based cancer registries in low- and middle-income countries, to ensure that countries are informed by real data.
The Global Initiative for Cancer Registry Development (GICR) is a multi-partner initiative, led by IARC, that works to reduce existing inequities in data availability.
There are huge inequities across the globe in access to life-saving innovations, and IARC is striving to minimize such inequities through research.
Although about 80% of deaths from cervical cancer occur in low-income and lower-middle-income countries, fewer than 25% of girls in such countries have access to HPV vaccination. Access to cervical cancer screening is even lower: fewer than 5% of women in many of these countries are ever screened.
Only 22 of the 78 low-income and lower-middle-income countries have introduced HPV vaccination into their national immunization programmes. This is either because policy-makers do not consider prevention of cervical cancer to be a priority or because the vaccine is not affordable for the health systems.
IARC is a major stakeholder in the recent WHO call to action to eliminate cervical cancer as a public health problem, and IARC supports advocacy for both HPV vaccination and cervical screening.
In Europe, the European Code Against Cancer is an excellent evidence-driven tool to convince both individuals and policy-makers of the benefits of HPV vaccination, among other effective cancer prevention interventions.
In 2009, IARC initiated a research project in India to evaluate the efficacy of a single dose of the quadrivalent HPV vaccine administered to unmarried girls aged 10–18 years. IARC is also taking part in a research project in Costa Rica, to provide important evidence of the efficacy of a single dose of the bivalent and nonavalent HPV vaccine. Early results from India and Costa Rica have demonstrated that a single dose of the vaccine might be as effective as two or three doses of the vaccine. However, these trials are still under way, and researchers are waiting for more mature results to emerge.