Results from the study published online on 4 December 2019 in The Lancet Global Health provide updated estimates of the cervical cancer burden 10 years after the 2008 GLOBOCAN publication1. In particular, cervical cancer remained a major public health problem, ranking in 2018 as the fourth most common cause of cancer incidence and mortality in women worldwide. Ten years ago, cervical cancer ranked as the third most common cancer among women worldwide, but in 42 low-resource countries, it was the most common cancer in women.
In 2018, the study team observed a significant positive correlation between national age-standardised incidence rate (ASIR) and corresponding estimates of human papillomavirus (HPV) prevalence. The 2018 estimates provide a baseline to measure the future achievements regarding the ambitious rollout of the World Health Organization (WHO) Global Initiative to eliminate cervical cancer as a public health problem in every country of the world.
The Global Cancer Observatory (GLOBOCAN) is a regularly-updated database, compiled by the International Agency for Research on Cancer, of global estimates of incidence and mortality rate for 36 cancers and for all cancers combined. For compiling the estimates, recorded data of high quality from national or subnational cancer registry sources are used where possible, otherwise the best available local sources are used in their absence.
Previous GLOBOCAN estimates for 2008 indicated that approximately 530 000 cervical cancer cases and 275 000 deaths had occurred worldwide, with 85% of cases occurring in less developed countries. The estimated annual ASIR was 15 per 100 000 women globally and ranged from less than 1 to 56 per 100 000. Cervical cancer was the leading cause of cancer-related death among women in sub-Saharan Africa, central America, south-central Asia, and Melanesia.
For this new worldwide analysis, the study team used data of cancer estimates from 185 countries from the GLOBOCAN 2018 database. Countries were grouped in 21 subcontinents and were also categorised as high-resource or lower-resource countries, on the basis of their Human Development Index.
The researchers calculated the number of cervical cancer cases and deaths in a given country, directly age-standardised incidence and mortality rate of cervical cancer, indirectly standardised incidence ratio and mortality ratio, cumulative incidence and mortality rate, and average age at diagnosis.
Approximately 570 000 cases of cervical cancer and 311 000 deaths from the disease occurred in 2018. Cervical cancer was the fourth most common cancer in women, ranking after breast cancer (2.1 million cases), colorectal cancer (0.8 million) and lung cancer (0.7 million).
The estimated age-standardised incidence of cervical cancer was 13.1 per 100 000 women globally and varied widely among countries, with rates ranging from less than 2 to 75 per 100 000 women. Cervical cancer was the leading cause of cancer-related death in women in eastern, western, middle, and southern Africa. The highest incidence was estimated in Eswatini, with approximately 6.5% of women developing cervical cancer before age 75 years. China and India together contributed more than a third of the global cervical burden, with 106 000 cases in China and 97 000 cases in India, and 48 000 deaths in China and 60 000 deaths in India.
Globally, the average age at diagnosis of cervical cancer was 53 years, ranging from 44 years in Vanuatu to 68 years in Singapore. The global average age at death from cervical cancer was 59 years, ranging from 45 years in Vanuatu to 76 years in Martinique.
Cervical cancer ranked in the top three cancers affecting women younger than 45 years in 146 (79%) of 185 countries assessed.
The global scale-up of HPV vaccination and HPV-based screening has potential to make cervical cancer a rare disease in the decades to come. New tools of primary prevention, such as prophylactic HPV vaccination and secondary prevention, namely screening with validated HPV assays and treatment of cervical precancerous lesions have been shown to be effective. The ambition of WHO is to reduce the ASIR of cervical cancer to less than 4 per 100 000 women worldwide by vaccinating 90% of all girls by age 15 years, screening 70% of women twice in the age range of 35–45 years, and treating at least 90% of all precancerous lesions detected during screening.
Modellers have estimated that this goal might be reached within a few decades in high-resource countries, but might take until the end of the 21st century for the goal to be reached in the lowest-resource countries. Nevertheless, the return of investment will be highest in low-resource countries. By using the cumulative incidence estimates from GLOBOCAN and assuming 70% HPV vaccination effectiveness, only 20 girls would need to be vaccinated in Eswatini, the country with the highest estimated incidence to avoid one case of cervical cancer, whereas the equivalent number needed would be 238 girls in the USA.
Ensuring the availability of recorded data of good quality from population-based cancer registries will be essential for monitoring local progress towards the cervical cancer elimination goal.
The authors concluded that most cervical cancers and related deaths can be avoided by integrated HPV-based screening and vaccination. WHO is developing a global plan of action to engage stakeholders and mobilise resources to make cervical cancer a rare disease globally through an ambitious scale-up of national services over the next decades. The GLOBOCAN 2018 figures presented in this study are pivotal to provide a baseline for the targets of the global strategy that will be submitted for ratification by WHO Member States at the 2020 World Health Assembly.
The study was funded by theBelgian Foundation Against Cancer, DG Research and Innovation of the European Commission, and The Bill & Melinda Gates Foundation.
Citation
1Arbyn M, Castellsagué X, de Sanjosé S, et al.Worldwide burden of cervical cancer in 2008. Ann Oncol 2011; 22: 2675-2686.
Reference
Arbyn M, Weiderpass E, Bruni L, et al. Estimates of incidence and mortality of cervical cancer in 2018: a worldwide analysis. The Lancet Global Health; Published online 4 December 2019. DOI: https://doi.org/10.1016/S2214-109X(19)30482-6