A new analysis of population-based estimates from 185 countries and territories revealed disparities in cancer incidence and mortality among men globally, with these disparities projected to widen by 2050.
The study, published in Cancer, provided a comprehensive look at the burden of 30 cancer types in men across age groups, countries, and levels of development.
Methods
Researchers used 2022 GLOBOCAN estimates to analyze cancer statistics for men in 185 countries. Mortality-to-incidence ratios (MIRs) were calculated by dividing age-standardized mortality rates (ASMRs) by age-standardized incidence rate (ASIRs). Projections for 2050 were derived through demographic projections, assuming 2022 rates remain constant.
Key Findings
In 2022, there were an estimated 10.3 million new cancer cases and 5.4 million cancer deaths among men globally. Nearly two-thirds occurred in those aged 65 years and older. The global ASIR, ASMR, and prevalence per 100,000 men were 212.6, 109.8, and 178.8, respectively. Prostate cancer was the leading cancer in terms of incidence in about two-thirds of countries, while lung cancer was the leading cause of cancer death in about half. A high MIR, indicating poor survival, was observed for rare cancers (eg pancreatic, 90.9%), among older men (61%), and in low Human Development Index (HDI) countries (74%).
Between 2022 and 2050, cancer cases are projected to increase 84%, to 19 million, and deaths by 93%, to 10.5 million, with the greatest increases in low and medium HDI countries (≥ 160%) and among men aged 65 years and older (≥117%).
Results by Cancer Type
The top five cancers by incidence in 2022 were lung (1.57 million cases), prostate (1.47 million), colorectal (1.07 million), liver (600,676), and stomach (627,458). The top five cancers by mortality in 2022 were lung (1.23 million deaths), liver (521,826), colorectal (499,775), stomach (427,575), and prostate (397,430). The highest MIRs were for pancreatic (90.9%), liver (85.8%), and esophageal (85.5%) cancers. Thyroid cancer had the lowest MIR (7.6%). Incidence is projected to increase most for mesothelioma (105.5%), bladder (100.9%), and colorectal (85.2%) cancers from 2022 to 2050; mortality is projected to increase most for prostate (136.4%), bladder (125.0%), and kidney (94.5%) cancers.
Results by Age
In 2022, adolescents and young adults (15-39 years) had an ASIR of 28.9 and an ASMR of 10.6 per 100,000. Middle-aged men (40-64 years) had an ASIR of 338.9 and an ASMR of 163.3 per 100,000. Two-thirds of cancer cases and deaths in 2022 occurred in those aged 65 years and older; by 2050, cases in this age group are projected to increase by 116.8% and deaths by 124.5%. Among the working-age group (15-64 years), cases are projected to increase by 39.1% and deaths by 39.9% from 2022 to 2050.
Results by Region and HDI
In 2022, ASIRs ranged from 110.0 per 100,000 in Southeast Asia to 307.6 per 100,000 in Europe. ASMRs ranged from 76.4 per 100,000 in Southeast Asia to 136.2 per 100,000 in Europe. Very high HDI countries had an ASIR three times that of low HDI countries (320.6 vs 98.9 per 100,000) but an ASMR only 1.7 times as high (118.3 vs 72.2 per 100,000). The highest MIR was in Africa (72.6%) and the lowest was in the Americas (39.1%). MIRs decreased with increasing HDI, from 73.5% in low HDI countries to 41.1% in very high HDI countries. From 2022 to 2050, cancer cases are projected to increase most in Africa (153.8%) and the Eastern Mediterranean (131.0%). Europe is projected to have the smallest increase (40.6%).
Results by Country
Australia had the highest ASIR (514.3 per 100,000), while Niger had the lowest (74.2 per 100,000). The highest ASMR was in Mongolia (227.5 per 100,000) and the lowest was in Saudi Arabia (81.0 per 100,000). Countries with the highest projected increases in cases from 2022 to 2050 include Benin (269%), Niger (265%), and Angola (262%). Those with the smallest projected increases include Bulgaria (3%), Japan (5%), and Portugal (6%). Countries with the highest projected increases in deaths from 2022 to 2050 include Benin (290%), Niger (273%), and Angola (268%). Those with the smallest projected increases include Bulgaria (13%), Latvia (14%), and Estonia (15%).
Conclusions
The study had several limitations that should be considered when interpreting the results, including data quality, projections assumptions, MIR interpretation, exclusion of other burden measures, and potential underestimation.
The findings of this study built upon and extended previous global cancer burden studies. The results supported those of Coleman et al. (2008) and Allemani et al. (2018), who found significant disparities in cancer survival between countries with different levels of economic development. This study provided more recent estimates and projections, incorporating data up to 2022 and projecting to 2050. Additionally, the focus on men and the inclusion of the MIR as a metric offered new insights into gender-specific cancer burden and outcomes. Unlike some previous studies that focused on specific cancer types or regions, this comprehensive analysis of 30 cancer types across 185 countries provided a more holistic view of the global cancer landscape among men.
The researchers noted that the projections may be influenced by emerging factors not accounted for in the current models. For instance, climate change could potentially impact cancer incidence through increased exposure to environmental carcinogens or changes in lifestyle factors. Conversely, advancements in cancer prevention, early detection technologies, and treatment modalities could significantly alter the projected cancer burden. The ongoing development of artificial intelligence in cancer diagnostics and the potential for personalized medicine could lead to earlier detection and more effective treatments, potentially reducing mortality rates. These factors underscored the need for continual updating of cancer burden projections as new data and trends emerge.
The authors concluded that the wide-ranging data highlighted the need for targeted interventions and global cooperation to address the disproportionate and growing burden of cancer among men, particularly in lower HDI countries and regions.
The authors declared no conflicts of interest.