International Cancer Research Organization IARC: HPV vaccination of school-age girls will reduce cervical cancer patients by more than 90%!

2021-04-17 Original by Dr.neuro MedSci

The study provides detailed estimates of the increasing burden of cervical cancer and the expected impact of HPV vaccination, with immediate implications for public health policymakers.

Cervical cancer is the fourth most common cancer in women worldwide and the largest source of cancer-related mortality among women in sub-Saharan Africa. Data show that in 2018, there were about 570,000 new cases of cervical cancer and 310,000 deaths. There are still significant differences in incidence rates in different regions of the world, ranging from 2 to 85 cases per 100,000 women from 2008-12.

Human papillomavirus (HPV) is an important cause of cervical cancer. Effective preventive vaccines against the most common high-risk HPV types in cervical cancer have been available for more than 10 years and have now shown a high degree of safety and efficacy against persistent HPV infection, precancerous lesions and invasive cervical cancer. Thus HPV vaccination regimens have proven to be cost-effective on a wide scale worldwide.

However, different regions face multiple hurdles in including HPV vaccination as part of their national expanded immunization programmes. These barriers include shortages of vaccine supplies, budget constraints, vaccine disruptions, and the inability to continuously connect medical services, as has happened during the COVID-19 pandemic.

As a result, as of 2019, only 96 countries (mostly high-income countries) have introduced the vaccine. In addition, in many countries, HPV vaccine coverage among school-age girls falls far short of the World Health Organization (WHO) recommendation that 90% of girls complete HPV vaccination by age 15.

WHO has launched an initiative to eliminate cervical cancer as a public health problem. Recently, IARC, an international organization for cancer research under the WHO, published the Lancet Public Health, a subsidiary of the Lancet, to predict the burden of cervical cancer and the impact of HPV vaccination on girls of the right age in different countries and regions around the world.

The expected number of cervical cancer cases in girls born between 2005 and 2014 in the absence of vaccination was estimated by combining the 2018 GLOBOCAN age-specific incidence rates and the United Nations population projections for age-specific mortality rates. The number of preventable cancers was estimated based on the reduction in HPV prevalence attributable to vaccination and the relative contribution of each HPV type to cervical cancer incidence.

The results show that globally, without vaccination, the current burden of cervical cancer in women aged 6-15 years (i.e. born in 2005-2014) is expected to reach 11.6 million cases by 2094. Of this, about 75% of the burden will be concentrated in 25 countries, mainly in Africa and Asia, where the number of cases is expected to increase exponentially in the future.

As the country with the largest population base, China is naturally one of the countries with the highest burden of cervical cancer. Data show that there are currently nearly 80 million girls of school age in China. If they are not vaccinated, 868,000 will develop cervical cancer before 2094. In other words, 11 out of every 1,000 girls will have cervical cancer.

The researchers further found that if the nine-valent HPV vaccine is administered and the prevention of HPV types 31, 33, 45, 52, and 58 is increased, the number of preventable cervical cancer cases in the world will increase to 10.2 million (88%), and China will increase the number of cervical cancer cases. Prevent 786,000 cases (90.6%) of cervical cancer!

In addition, demographic changes will also affect the future age distribution of cervical cancer. In 2018, 72.7% of global cases occurred before the age of 60, with a similar age distribution of cases across continents. In contrast, among women born between 2005 and 2014, 53.6% of future cervical cancers (6.2 million cases) are expected to occur before the age of 60 in the absence of vaccination.

Taken together, this study provides detailed estimates of the increasing burden of cervical cancer and the expected impact of HPV vaccination, with immediate implications for public health policymakers.

Reference：

Global estimates of expected and preventable cervical cancers among girls born between 2005 and 2014: a birth cohort analysis.?https://doi.org/10.1016/S2468-2667(21)00046-3

The Human Papillomavirus Real Time PCR Kit is an in-vitro diagnostic (IVD) kit, based on real-time PCR technology, for the detection of 18 HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68, 73, 53, 82, and 26) in cervical exfoliated cells in one reaction well. The kit identifies HPV16, HPV18, other HPV types and internal control (β-globin) using fluorescence channels: FAM, VIC, ROX and CY5. This kit contains primers and probes that are designed to target the L1, L2, and E1 genes of 18 HPV types. The amplicon length of each HPV type does not exceed 200 bp. A PCR fluorescence detection system is used to record the change in fluorescence emitted by the fluorescent probe at each PCR cycle during PCR amplification, which directly reflects the change in the PCR amplification yield.