Karen Canfell, DPhil
In a modeling study reported in The Lancet Oncology, Karen Canfell, DPhil, and colleagues detailed the preventive effects on cervical cancer that could be achieved by scaled-up human papillomavirus (HPV) vaccination and cervical screening efforts with the aim of disease elimination.
The major modeling projections are summarized below:
- With no further intervention, 44.4 million cervical cancer cases would be diagnosed globally over the period 2020–2069, with almost two-thirds of cases occurring in low–Human Development Index (HDI) or medium-HDI countries.
- Rapid scale-up of vaccination to 80% to 100% coverage globally by 2020 with a broad-spectrum HPV vaccine could avert 6.7 to 7.7 million cases in this period—but more than half of these cases would be averted after 2060. Implementation of HPV-based screening twice per lifetime at age 35 years and 45 years in all low- or middle-income countries with 70% coverage globally would move the effects of prevention forward and avert a total of 12.5 to 13.4 million cases in the next 50 years.
Rapid scale-up of combined high-coverage screening and vaccination from 2020 onwards would result in the average annual cervical cancer incidence declining to < 6 new cases per 100,000 women by 2045–2049 for very high–HDI countries; by 2055– 2059 for high-HDI countries; by 2065–2069 for medium-HDI countries; and by 2085–2089 for low-HDI countries. Moreover, the same rapid scale-up would lead to < 4 new cases per 100,000 women by 2055–2059 for very high–HDI countries; by 2065– 2069 for high-HDI countries; by 2070–2079 for medium-HDI countries; and by 2090–2100 or beyond for low-HDI countries.
More gradual scale-up over the period 2020 to 2050 (eg, 20%–45% vaccination coverage and 25%–70% once-per-lifetime screening coverage by 2030, increasing to 40%–90% vaccination coverage and 90% once-per-lifetime screening coverage by 2050) would lead to end of the century incidence rates per 100,000 women of 0.8 cases in very high–HDI countries, 1.3 cases in high-HDI countries, 4.4 cases in medium-HDI countries, and 14 cases in low-HDI countries.
Study Implications
The investigators concluded, “More than 44 million women will be diagnosed with cervical cancer in the next 50 years if primary and secondary prevention programs are not implemented in [low- and middle-income countries]. If high coverage vaccination can be implemented quickly, a substantial effect on the burden of disease will be seen after three to four decades … widespread coverage of both HPV vaccination and cervical screening from 2020 onwards has the potential to avert up to 12.5–13.4 million cervical cancer cases by 2069, and could achieve average cervical cancer incidence of around four per 100,000 women per year or less, for all country HDI categories, by the end of the century.” ■
