The burden of cervical cancer remains high in many countries and needs to be scaled up to meet the WHO elimination goal by 2030.
Highlights
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Cervical cancer is a global public health problem, with a particularly high burden in many low- and middle-income countries (LMICs). The demonstrated effectiveness of intervention measures, such as vaccination against the most oncogenic types of human papillomavirus (HPV) (the main cause of cervical cancer) and screening, particularly with HPV-based methods, mean that Cervical cancer is a largely preventable disease.
However, progress in terms of reducing cervical cancer incidence and mortality has so far been predominantly seen in countries with a high Human Development Index (HDI), where high-quality screening services, timely treatment and Follow-up care is routine and available. In LMICs, where the vast majority of cases and deaths occur, progress in reducing incidence and mortality has been slow, with several countries reporting increases in incidence or mortality rates over the past decade.
In 2020, WHO launched the Global Cervical Cancer Elimination Initiative to accelerate the elimination of cervical cancer with the goal of reducing incidence below a threshold of 4 cases per 100,000 women-years in all countries. and thus reduce the international disparities associated with this disease. The 90–70–90 goal set by the initiative to achieve by 2030 requires that 90% of girls be vaccinated by age 15, 70% of women undergo a high-throughput test at least twice before of 45 years, and 90% of women identified with cervical precancer or cancer to be treated. The WHO elimination strategy has emphasized the need for continued and improved surveillance and monitoring of cervical cancer as a critical step for action that will enable program managers to identify gaps and take targeted action.
Cancer incidence and mortality data collected by the International Agency for Research on Cancer (IARC) provide the opportunity to estimate the burden of cervical cancer across countries and regions of the world over several decades. Therefore, in this study, we aimed to evaluate the global epidemiological landscape of cervical cancer in 2020 along several axes, including geographic and socioeconomic development, and considering temporal dynamics, using high-quality databases.
Summary
Background
Monitoring progress and providing timely evidence is a critical step for countries to remain aligned with the goals set by WHO to eliminate cervical cancer as a public health problem (i.e., to reduce the incidence of the disease below the threshold of 4 cases per 100,000). woman-years). We aimed to assess the extent of global inequalities in cervical cancer incidence and mortality, as estimated by The Global Cancer Observatory (GLOBOCAN) 2020, including geographic and socioeconomic development, and temporal aspects.
Methods
For this analysis, we used the GLOBOCAN 2020 database to estimate age-specific and age-standardized cervical cancer incidence and mortality rates per 100,000 women-years for 185 countries or territories aggregated in the 20 global regions defined by the UN, and by levels of four levels of the Human Development Index (HDI). Temporal trends (1988–2017) in incidence were extracted from the Cancer Incidence in Five Continents (CI5) plus database . Mortality estimates were obtained using the most recent WHO national vital registration data.
Results
Globally in 2020, there were an estimated 604,127 cases of cervical cancer and 341,831 deaths, with a corresponding age-standardized incidence of 13.3 cases per 100,000 women-years (95% CI: 13.3 –13.3) and mortality rate of 7·2 deaths per 100,000 women-years (95% CI 7·2–7·3). The incidence of cervical cancer ranged from 2·2 (1·9–2·4) in Iraq to 84·6 (74·8–94·3) in Eswatini. Mortality rates ranged from 1·0 (0·8–1·2) in Switzerland to 55·7 (47·7–63·7) in Eswatini.
The age-standardized incidence was highest in Malawi (67.9 [95% CI 65.7-70.1]) and Zambia (65.5 [63.0-67.9]) in Africa, Bolivia (36, 6 [ 35·0–38·2]) and Paraguay (34·1 [32·1–36·1]) in Latin America, Maldives (24·5 [17·0–32·0]) and Indonesia (24· 4 [24·2–24·7]) in Asia, and Fiji (29·8 [24·7–35·0]) and Papua New Guinea (29·2 [27·3–31·0]) in Melanesia .
There is a clear socioeconomic gradient in cervical cancer, with decreasing rates as the HDI increases. Incidence was three times higher in low HDI countries than in very high HDI countries, while mortality rates were six times higher in low HDI countries than in very high HDI countries.
In the 2020 estimates, an overall decline in incidence was observed in most countries around the world with representative trend data, and incidence stabilized at relatively low levels around 2005 in several high-income countries. In contrast, in the same period the incidence increased in some countries in East Africa and Eastern Europe.
We observed different patterns of age-specific incidence between countries with well-developed population-based screening and treatment services (e.g., Sweden, Australia, and the United Kingdom) and countries with insufficient and opportunistic services (e.g., Colombia , India and Uganda).
Interpretation
The burden of cervical cancer remains high in many parts of the world and, in most countries, the incidence and mortality of the disease remain well above the threshold set by the WHO initiative on cancer elimination. of cervix.
We identified substantial geographic and socioeconomic inequalities in cervical cancer globally, with a clear gradient of increasing rates for countries with lower levels of human development.
Our study provides timely evidence and impetus for future strategies that prioritize and accelerate progress toward WHO elimination goals and, in doing so, address the marked variations in the current global cervical cancer landscape.
Money
French National Cancer Institute, European Commission Horizon 2020 Framework Program for Research and Innovation; and EU4Health Program.
Comments
There were more than 600,000 new cases of cervical cancer and more than 340,000 deaths worldwide in 2020, according to an observational study published in the journal The Lancet Global Health .
While cervical cancer has declined in many regions of the world over the past three decades—especially in Latin America, Asia, Western Europe, and North America—the burden remains high in many low- and middle-income countries.
The development of effective HPV vaccination and screening programs has made cervical cancer a largely preventable disease. In 2020, the World Health Organization (WHO) announced a target to accelerate the elimination of cervical cancer as a public health problem, with the goal of reducing incidence below a threshold of four cases per 100,000 women. per year in all countries by 2030. This study tracks progress in cervical cancer rates and identifies countries and regions where efforts must increase to achieve WHO targets.
Dr Deependra Singh, International Agency for Research on Cancer (IARC)/WHO, France, says: “HPV screening and vaccination technologies mean that cervical cancer is now largely preventable. Our study finds encouraging declines in some high-income countries following the successful implementation of HPV vaccination and screening programs, such as in Sweden, Australia, and the United Kingdom, but globally the burden remains high. “Around the world, women should be free from the risk of preventable cancer, and with the development of effective vaccines and screenings over the past 20 years, we have the tools to make this a reality.”
The study used IARC’s GLOBOCAN 2020 database to estimate the burden of cervical cancer incidence and mortality rates in 185 countries. Additionally, the study analyzed the relationship between cervical cancer cases and deaths in relation to national levels of socioeconomic development. Finally, the authors looked at data from 1988 to 2017 to identify increasing and decreasing trends.
In 2020, cervical cancer case rates were 13 per 100,000 women per year and there were seven deaths per 100,000 women per year. Incidence rates in 172 of 185 countries still exceeded the WHO elimination threshold of four cases per 100,000 women per year.
Rates varied significantly between countries, with a 40-fold difference in cases and a 50-fold difference in deaths. Case rates ranged from two cases in Iraq to 84 cases in Eswatini per 100,000 women per year; while mortality rates ranged from one death in Switzerland to 56 deaths in Eswatini per 100,000 women per year.
There was substantial socioeconomic inequality in cervical cancer globally. There was a clear socioeconomic gradient in incidence and mortality, with higher rates observed in countries with less socioeconomic development.
Looking at trend data from 1988 to 2017, the authors observed significant declines in cases in some Latin American countries, including Brazil, Colombia and Costa Rica. A similar pattern was seen in Asia in India, Thailand and South Korea, as well as in Eastern Europe in Poland, Slovenia and the Czech Republic. However, there have been increases in cases in Eastern Europe, Latvia, Lithuania and Bulgaria, and East Africa in the last decade, as well as in the Netherlands and Italy. Reasons for recent increases could include a higher prevalence of HPV among younger generations of women and a lack of effective screening programs.
Countries with the largest average decreases in incidence rates per year included Brazil (8%), Slovenia (7%), Kuwait (7%), and Chile (6%); while the largest increases in rates occurred in Latvia (4%), Japan (3%), Ireland (3%), Sweden (3%), Norway (2%), Northern Ireland (2%), Estonia (2 %). , and China (2%).
Dr Valentina Lorenzoni, Scuola Superiore Sant’Anna, Italy, says: “Cervical cancer cases are much higher than the threshold agreed by the WHO initiative on eliminating cervical cancer in most countries. countries, indicating that there is still much work to be done before 2030. While a decrease in the intensity of screening due to the COVID-19 pandemic could have left a new group of women susceptible, the pandemic also prompted the introduction of self-administered HPV testing, offering new possibilities to increase screening coverage. Other new advances, such as thermal ablation to treat cervical precancer, the use of mobile phones to improve follow-up after screening, and machine learning to improve visual assessment, can also be used in low-resource settings to reduce cervical cancer rates.
Finally, the authors note that the estimates were based on the best available cancer data in each country, but caution that these may be incomplete or inaccurate. For example, cases may appear low in countries where there are no effective screening programs or limited data from local population-based cancer registries are available.
Research in context
Evidence prior to this study We searched PubMed from database inception through April 14, 2022, without language restrictions, for previously published studies addressing patterns and trends in cervical cancer using the following combination of words in titles or abstracts: “cervical cancer”, “incidence”, “mortality”, “trend”, “age-specific rates”. We also reviewed the references of the retrieved articles to identify additional studies, yielding a total of 264 studies, supplemented by four additional articles that were added based on the reviewers’ suggestions.
Published studies have reported that although the incidence of cervical cancer has decreased in many countries and regions of the world, the incidence is increasing in some settings, including some countries in East Africa and West Asia. Studies have reported a continued rise in the number of new cases globally, with the majority of cases and deaths concentrated in low- and middle-income countries, where progress in reducing the burden has been negligible compared to their counterparts across the globe. high income. Following the launch of the WHO Cervical Cancer Elimination Initiative (CCEI), with the goal of reducing incidence to the threshold of 4 cases per 100,000 woman-years or less in all countries of the world, it is important to establish statistics reference to monitor progress as the CCEI grows. The initial evaluation includes monitoring the geographic, temporal and socioeconomic evolution of cervical cancer, and how the risk of the disease evolves with age in settings with or without organized population screening programs.
Added value of this study
We have compared countries and regions around the world against the target set by the CCEI, providing a complete and up-to-date picture of the extent of global inequalities. GLOBOCAN 2020 estimates indicate that there are large variations between and within regions in the incidence of cervical cancer at the national level, with a 40- to 50-fold difference in incidence (ranging from 2 to 84 cases per 100 000 women) and mortality rates (ranging between 1 and 56 cases per 100 000 women). The incidence of 172 of the 185 countries or territories included in this analysis exceeded the threshold established by the CCEI.
We confirm findings of a clear socioeconomic gradient in incidence and mortality, with progressively lower rates observed as national Human Development Index values increase. We demonstrate that progress in reducing the burden of cervical cancer has been highly unbalanced across countries and regions of the world over the past two decades, with the positive impact of mass population-based screening programs visible exclusively in countries of high income. This study provides timely evidence and impetus for national strategies that address the increasing burden of cervical cancer now and in the coming decades.
Implications of all available evidence
This study emphasizes equitable resource allocation and access to services as key elements in reducing disparities in cancer outcomes. Within the CCEI’s ultimate goal of reducing the incidence of cervical cancer below a threshold of 4 cases per 100,000 woman-years, the sustainable expansion of population-based cancer registries in all countries of the world represents a crucial gold standard for monitoring progress in meeting the 90–70–90 targets as part of the nationwide elimination strategy.
