The World Health Organization’s (WHO) cancer agency, the International Agency for Research on Cancer (IARC), has released updated findings of the current global burden of cancer alongside World Cancer Day on February 4, 2023. The WHO indicated that a majority of countries do not adequately finance priority cancer and palliative care services as part of universal health coverage.
Updated IARC Estimates
In the IARC’s resource, the Global Cancer Observatory, investigators examined the major types of cancers and the leading causes of cancer mortality in 2022 to highlight the growing burden of cancer, the disproportionate impact on underserved populations, and the urgent need to address cancer inequities worldwide. They included 185 countries and 36 different cancer types in their analysis.
The investigators reported that in 2022, there were an estimated 20 million new cancer cases and 9.7 million deaths from the disease. They estimated that 53.5 million patients experienced 5-year survival following diagnosis. About 20% of individuals may develop cancer in their lifetime, and approximately 11.1% and 8.3% of men and women will die from the disease, respectively.
The investigators discovered that 10 types of cancers collectively comprised around 67% of the new global cancer cases and deaths in 2022. Lung cancer was found to be the most commonly occurring cancer type worldwide with 2.5 million new cases accounting for 12.4% of the total new cases. Breast cancer in female patients ranked second (2.3 million cases, 11.6%), followed by colorectal cancer (1.9 million cases, 9.6%), prostate cancer (1.5 million cases, 7.3%), and gastric cancer (970,000 cases, 4.9%).
Lung cancer was also the leading cause of cancer mortality with 1.8 million deaths accounting for 18.7% of the total cancer deaths, followed by colorectal cancer (900,000 deaths, 9.3%), hepatic cancer (760,000 death, 7.8%), breast cancer (670,000 deaths, 6.9%), and gastric cancer (660,000 deaths, 6.8%). Lung cancer’s reemergence as the most common cancer type may have been related to the persistent use of tobacco across Asian countries.
The investigators found some disparities in the global incidence and mortality of cancer by sex. For women, the most commonly diagnosed cancer type and leading cause of cancer mortality was breast cancer, whereas for men, it was lung cancer. Breast cancer was the most common cancer type in women in 85% (n = 157) of the countries. For men, prostate cancer and colorectal cancer were the second and third most commonly occurring cancer types, while hepatic cancer and colorectal cancer were the second and third most common causes of cancer mortality, respectively. For women, lung cancer and colorectal cancer were the second and third leading cause of cancer incidence and mortality, respectively.
Cervical cancer was the eighth most commonly occurring cancer type globally and the ninth leading cause of cancer mortality, accounting for 661,044 new cases and 348,186 deaths. It was also the most common cancer type in women in 13.5% (n = 25) of the countries, many of which were in sub-Saharan Africa. Even while recognizing varying incidence levels, the investigators emphasized that cervical cancer may be eliminated as a public health problem through the scale-up of the WHO Cervical Cancer Elimination Initiative.
Global estimates revealed striking inequities in the cancer burden according to human development. In countries with a very high Human Development Index, 8.3% (n = 1/12) of women may be diagnosed with breast cancer in their lifetime and 1.4% (n = 1/71) of women may die from the disease. By contrast, in countries with a low Human Development Index, although only 3.7% (n = 1/27) of women may be diagnosed with breast cancer in their lifetime, 2.1% (n = 1/48) of them may die from the disease.
“Women in lower [Human Development Index] countries are 50% less likely to be diagnosed with breast cancer than women in higher [Human Development Index] countries, yet they are at a much higher risk of dying of the disease due to late diagnosis and inadequate access to quality treatment,” explained Isabelle Soerjomataram, MD, PhD, Deputy Head of the Cancer Surveillance Branch at the IARC.
Findings From the WHO Survey
In the new global survey on universal health coverage and cancer, the WHO examined the cancer care services of 115 countries. The survey revealed that only 39% of the participating countries covered the basics of cancer management as part of their financed core health services for all citizens (health benefit packages) and only 28% of the countries additionally covered care for patients who require palliative care, including pain relief.
The WHO’s global survey of health benefit packages also demonstrated significant global inequities in cancer care services. For instance, lung cancer–related services were reportedly 4 to 7 times more likely to be included in a health benefit package in a high-income country compared with a lower-income country. On average, there was a fourfold greater likelihood of radiation services being covered in a health benefit package in a high-income vs lower-income country. The widest disparity for any service was stem-cell transplantation, which was 12 times more likely to be included in a health benefit package in a high-income country.
Projections for 2050
The investigators predicted that there may be 35 million new cancer diagnoses in 2050, a 77% increase from the estimated 20 million cases in 2022. The rapidly growing global cancer burden may represent both an aging and growing population as well as changes to individual’s exposure to cancer risk factors such as tobacco, alcohol, obesity, and air pollution—several of which may be associated with socioeconomic development.
In terms of the absolute burden, high Human Development Index countries are expected to experience the greatest absolute increase in cancer incidence, with an additional 4.8 million new cases predicted in 2050 compared with in 2022. However, the proportional increase in incidence may be highest in low Human Development Index countries (142% increase) and in medium Human Development Index countries (99%). Similarly, cancer mortality in these countries is projected to almost double by 2050.
“The impact of this increase will not be felt evenly across countries of different [Human Development Index] levels. Those who have the fewest resources to manage their cancer burdens will bear the brunt of the global cancer burden,” underscored Freddie Bray, MSc, PhD, Head of the Cancer Surveillance Branch at the IARC.
Conclusions
“[The] WHO’s new global survey sheds light on major inequalities and lack of financial protection for cancer around the world—with populations, especially in lower income countries, unable to access the basics of cancer care,” stressed Bente Mikkelsen, MHA, Director of the Department of Noncommunicable Diseases at the WHO. “[The] WHO, including through its cancer initiatives, is working intensively with more than 75 governments to develop, finance, and implement policies to promote cancer care for all. To expand on this work, major investments are urgently needed to address global inequities in cancer outcomes,” she added.
“Despite the progress that has been made in the early detection of cancers and the treatment and care of patients [with cancer], significant disparities in cancer treatment outcomes exist not only between high- and low-income regions of the world, but also within countries. Where someone lives should not determine whether they live. Tools exist to enable governments to prioritize cancer care and to ensure that everyone has access to affordable, quality services. This is not just a resource issue but a matter of political will,” concluded Cary Adams, BSc (Hons), MBA, Head of the Union for International Cancer Control.
Disclosure: For full findings on the global burden of cancer, visit gco.iarc.fr.
