Global cancer statistics: A healthy population relies on population health

Abstract

The 2022 update on cancer statistics provides a staggering figure: 20 million will receive a new diagnosis of cancer, and nearly 10 million will die. The data are derived from estimates provided by the Global Cancer Observatory, which relies on the best available sources of both incidence and mortality from cancer in each country.¹ Population-based cancer survival is a key metric of the effectiveness of health systems in how cancer is managed in individual countries. The monitoring of trends and inequalities in cancer survival is an important metric of overall health system performance, is used to guide investment priorities within oncology, and can help advance locally informed, cost-effective interventions to improve early diagnosis and treatment.

However, we believe there is a major caveat in these figures, which should serve as a flag for all who seek to prevent cancer from occurring or aim to convert it from a deadly disease to one that people live through, if not with; the data are only as valid as they are representative of a true country's burden. As such, the quality of the source information matters greatly, yet only 1% of African countries and 4% of Asian, South American, and Central American countries collect sufficient data for use.² For now, the Global Cancer Observatory does its best with what it has and thus can provide estimates for all parts of the world. To be frank, the lack of high-quality, country-specific cancer registries, particularly in low-income and middle-income countries (LMICs), affects the accuracy of these figures, raising the concern that these estimates are in fact underestimating both the incidence of and mortality from cancer. Moreover, whether trends in cancer by age at diagnosis are mirrored across countries is important to understand. For example, as the report notes, high Human Development Index (HDI) countries are reporting a rise in colorectal cancer diagnoses before age 50 years. Whether people living in lower HDI countries are experiencing the same trend is not known.

These issues are brought to the forefront when one looks at two countries in different parts of the world: Bangladesh and the Republic of Georgia. In Bangladesh, cancer incidence and mortality are based on cancer registries at the hospital level, hiding from view those who are not able to access specialized care, which is often centered in the major cities, like Dakha. As such, conclusions in this report that suggest the risk of developing cancer trends with increasing HDI, although firmly backed by the available data, need to be read with this important restriction in mind. In Georgia, the lack of a nationwide registry was recognized as a significant unmet need over a decade ago; and, in 2011, the Georgian government funded the State Program of Modern Cancer Registry Implementation. With significant support from the International Agency for Research on Cancer (IARC), work between 2011 and 2014 was initiated to build the workforce and infrastructure to realize this goal, and the population-based registry was launched in 2015, with a new imperative to modernize data collection from paper to electronic means starting in 2019. The system is now connected to other demographic data, including birth and death records. This allows the vital status of registered patients with cancer to be obtained through passive follow-up, by linkage between the registry data and the national mortality database.

Beyond screening, this report highlights another salient point: from a global perspective, the access to effective prevention and screening methods is not equitable. Take the risk of lung cancer, which the report discusses at length. Smoking remains an issue in many areas of the world, even as rates in high HDI countries stabilize or even decline. Georgia has one of the highest smoking prevalences among the European countries. In 2017, tobacco-control bills were adopted by the Parliament of Georgia, including bans on smoking in all public transport and buildings, on smoking advertisements, on any sponsorship or promotion of tobacco, on smoking accessories and devices, and on the display of smoking at points of sales, with restriction on smoking as it is portrayed in film and other entertainment forms. This implementation now is intimately a part of the State Program on Health Promotion, which includes training of staff and providers on smoking cessation, the monitoring of enforcement of smoke-free legislation in public premises, developing novel communication tools, and creating school education materials for the country. Despite the strides made by the Georgian Government, this country still faces an uphill battle because of the tobacco industry.

Efforts to detect breast cancer at an earlier stage through the implementation of mammographic screening continues to be a challenge as well, despite the higher mortality rates of breast cancer seen in lower versus higher HDI countries. As such, individuals with breasts face a greater chance of presenting with symptomatic and/or more advanced disease. In Georgia, cancer screening (breast, cervix, and colorectal) has been available for 16 years through national programs. Yet there are low uptake rates to screening, and we continue to see people presenting with advanced breast cancer. This highlights the importance of cultural humility—communication and education about early detection must make sense to the population it seeks to help, and this starts by identifying the barriers and concerns within them.

Prevention efforts should be more widely available given the availability of evidence-based prevention measures, including treatment for Helicobacter pylori and vaccines against both human papillomavirus (HPV) and hepatitis B virus (HBV). This also takes governmental partnership and buy-in. The Government of Georgia and international partners supported the introduction of organized cervical cancer vaccination and screening programs, and, today, HPV vaccination is included in the national vaccination program schedule. The hepatitis B vaccine was introduced nationwide in 2001, and coverage has been ≥90% since 2010. In a nationwide serosurvey among adults in 2015, the prevalence was 2.9% (range, 2.4%–3.5%) for hepatitis B surface antigen and 25.9% (24.1%–27.6%) for antihepatitis B core antibody.³ Notably, in 2021, only 0.03% of children in Georgia were found to have chronic HBV infection, reflecting the success of the infant hepatitis B vaccination program implemented in 2001. With 2.7% of adults (an estimated 77,000 persons) infected in 2021, chronic HBV infection remains a problem among those born before the hepatitis B vaccine introduction. In Bangladesh, the efforts are still in their infancy. Although the government includes HBV vaccination as part of its extended vaccination program starting at infancy, the HPV vaccine is initiating as a pilot project, with the aim of administering a single dose of the bivalent vaccine to teenaged girls across the country and without cost.

For individuals with cancer in LMICs, the simple reality is that access to modern cancer treatment, particularly targeted cancer treatments, is extremely limited. In Bangladesh, multiple barriers exist to cancer drug development, which is an intrinsically time-consuming and expensive process, particularly in LMICs where the infrastructure and resources needed for drug development are not readily available. In Georgia, the population has access to the Universal Health Care Program, which includes access to cancer treatment for all citizens, regardless of income, within the framework of the Universal Health Care Program. Although treatment is financed, there is a cap which, without copayment, is 25,000 GEL ($9000 US dollars) annually. However, the costs of modern targeted treatment and/or immunotherapy far exceed this cap, and patients are expected to make up the difference. Consequently, limits are often expended quickly, and even before cancer treatment has started.

Although international partnerships and efforts, such as the World Health Organization Essential Medication List, can help improve access, unless the drugs are available in any one country, the discussion about access will be moot.⁴ Economic and access barriers exist in each country, whether they consist of the cost of any agent compared with the purchasing power of the country or the willingness of the pharmaceutical industry to engage with lower HDI regimens to make drugs available on trials. Still, lower HDI countries are attempting to respond. In Bangladesh, there are in-country production capabilities for both monoclonal antibodies and immunotherapy, and this type of production of biosimilar drugs can have a significant impact on cancer care in LMICs.⁵

In conclusion, this work on global statistics is of the utmost importance. We need to understand that the issue of cancer is an international concern, affecting each country regardless of their health system and access to care. However, understanding the scope of the issue requires a coordinated and sustained approach to data collection to ensure that the statistics are accounting for everyone diagnosed with cancer, as well as requiring continued collaboration in the efforts to bring global equity for cancer screening, treatment, and postcancer care. We will all thrive within a healthier population; and, no matter where you are in the world, no one deserves cancer.

Don S. Dizon reports stock options in Doximity and Midi; and service on Data and Safety Monitoring Boards at Clovis Oncology Inc., AstraZeneca, and GlaxoSmithKline, LLC, and consulting fees from Kronos Biotech and Pfizer, all outside the submitted work. Natia Jokhadze and Arunangshu Das disclosed no conflicts of interest.