Rapid scaling up of HPV vaccine and screening

Cervical cancer could be eliminated as a public health problem in most countries by the end of the century by rapidly expanding existing interventions, according to a modeling study published in The Lancet Oncology.

The estimates, which are the first of their kind on a global scale, indicate that the combination of high uptake of the human papillomavirus (HPV) vaccine and high cervical screening rates based on HPV in all countries from 2020 could prevent up to 13.4 million cases of cervical cancer by 5069 (by 2069), and the average rate of Annual cases in all countries could fall to less than four cases per 100,000 women by the end of the century – which is a potential threshold for considering cervical cancer eliminated as a problem major public health.

According to a more gradual staging scenario, the elimination of cervical cancer is expected in countries with very high and high rates of development by the end of the century, but average rates would remain at above the threshold in medium-rate countries (4.4 per 100,000) and low levels of development (14 per 100,000).

Without expanding current prevention programs, however, the study predicts that 44.4 million cases of cervical cancer would be diagnosed over the next 50 years, from 600,000 in 2020 to 1.3 million in 2069 due to population growth and aging.

In May 2018, the Director General of the World Health Organization (WHO) called for coordinated action at the global level to eliminate this highly preventable cancer. The findings of this study helped to inform initial discussions on phase-out objectives in the development of the WHO strategy, and future modeling studies will support the development of the final goals and targets for the WHO. elimination of cervical cancer.

WHO called for urgent action to scale up the implementation of proven measures to eliminate cervical cancer as a global public health problem (including HPV vaccination, screening and treatment precancer, early detection and early treatment of early invasive cancers and palliative care). A draft global strategy to accelerate the elimination of cervical cancer, with targets and targets for the 2020-2030 period, will be considered by the World Health Assembly in 2020.

"Despite the enormity of the problem, our results suggest that the global elimination is at hand with the tools already available, provided that it is possible to achieve high coverage of the HPV vaccination and uterine cervix screening, "says Professor Karen Canfell of the Cancer Council New South. Wales, Sydney, Australia who led the study.

"More than two-thirds of the cases averted would be in low- or medium-developing countries, such as India, Nigeria, and Malawi, where access to HPV vaccination or testing for Cervical cancer was so far limited.This action offers a huge opportunity to increase the level of investment in proven cervix cancer interventions. In the world's poorest countries, if these measures are not adopted, millions of preventable premature deaths would be avoided. "

Cervical cancer is the fourth most common cancer in women, with approximately 570,000 new cases diagnosed worldwide in 2018, of which approximately 85% are in less developed areas. HPV, a group of more than 150 viruses, is responsible for the majority of cervical cancers. Proven methods are available to detect and treat cervical pre-cancers, and broad-spectrum HPV vaccines can potentially prevent up to 84% to 90% of cervical cancers.

Nevertheless, there are wide disparities between countries in cervical cancer screening and HPV vaccination coverage. In low- and middle-income countries (LMICs), overall screening rates in 2008 were only 19%, compared with 63% in high-income regions; while in 2014, fewer than 3% of 10- to 20-year-old women in LMICs had received the full HPV vaccination cycle in 2014, compared to over one-third in high-income countries.

The authors badyzed high quality registry data from the International Agency for Research on Cancer to predict future trends in cervical cancer if no further action is taken. They then used a dynamic model to calculate the impact of intensifying HPV vaccination and uterine cervical screening on the burden of cervical cancer worldwide, and in 181 countries at all levels of development, between 2020 and the end of the century.

Modeling focuses on the deployment of immunization and screening in low- and middle-income countries rather than a detailed modeling of all the most recent improvements in high-development countries, which may have underestimated the time to elimination in individual countries with a high level of development. development.

The researchers also predicted the earliest date at which uterine cervix cancer rates could be sufficiently reduced to allow elimination (considering that a possible lower elimination threshold four cases per 100,000 people). The average worldwide age-standardized cervical cancer rate in 2012 was 12 per 100,000.

The results showed that a rapid vaccine coverage worldwide ranging from 80% to 100% by 2020 with the help of a broad-spectrum vaccine against HPV could prevent 6.7 to 7.7 million cases – but more than half of them would be avoided after 2060.

If, in addition, cervical cancer screening becomes high coverage by 2020 (all women being screened twice during their lifetime and 70% coverage worldwide), this could prevent 5, 7 to 5.8 million additional cases of cervical cancer over the next few years. 50 years and greatly accelerate the elimination.

These efforts could lead to the elimination of cervical cancer as a public health problem, with average rates in all countries falling to less than four cases per 100,000 by 2055 to 1959 in countries with very high levels of development (notably the United States, Finland, the United Kingdom and the United Kingdom). Canada); 2065-69 for high-growth countries (notably Mexico, Brazil and China); 2070-2079 for medium-developing countries (notably India, Vietnam and the Philippines); and 2090-2100 and higher for low-development countries (such as Ethiopia, Haiti, and Papua New Guinea).

However, rates of less than four cases per 100,000 population would not be reached by the end of the century in all African countries (for example, Kenya, Tanzania and Uganda), even though high coverage and screening of the cervix twice were possible. 2020.

The authors note several limitations, including that their predictions are limited by the lack of high quality data on the incidence of cancer over time, especially in developing countries. They also note that the model badumed the lifespan of vaccine protection and did not fully account for geographic differences in badual behavior, which could affect the accuracy of the estimates. They also badumed in their rapid-rise scenarios that very high overall vaccination coverage rates (80% or more) would be achievable worldwide – but it is probably difficult to provide two doses of HPV vaccine with appropriate spacing. less developed regions. Finally, the rapid development scenario examined in the study did not take into account cultural, logistical and financial barriers to scaling up testing in low-resource countries.

Source: The Lancet