Geographic, Sociodemographic Factors Significantly Influence AML in Elderly Patients

Although incidence and mortality rates, disability-adjusted life-years (DALYs), and estimated annual percentage change (EAPC) increased steadily over a 30-year period, the growing burden of acute myeloid leukemia (AML) was often higher in developed countries compared with developing regions, according to a report published in Frontiers of Public Health.

Diverse group of seniors

Image credit: Maria - stock.adobe.com

Globally, approximately 80% of new cases of AML occur in individuals aged 60 and older, the authors wrote. Compared with younger patients, older patients often face more complications and challenges in treatment, significantly affecting their prognosis and reducing their life expectancy, they said. AML has the highest mortality rate among the different types of leukemia.

The researchers explained that survival rates among younger patients have shown significant improvement over the years, while survival rates for older patients have seen only marginal progress.

“We aimed to provide a comprehensive analysis of the global burden of AML in older patients, contributing to the formulation of appropriate preventative and therapeutic measures against this disease,” they said.

To conduct this study, the investigators began by examining a wide range of information from 204 countries, 21 geographic regions, and 5 sociodemographic index (SDI) regions using the Global Burden of Disease database. The data included global, regional, and national incidence rates; incidence counts; mortality rates; mortality counts; DALYs rates and counts; and changes in case counts.

The investigators highlighted the annual number of incident cases, death cases, and DALYs cases for 1990 through 2019 and the change between them.

To ensure a comprehensive analysis, the researchers divided the global map into geographical regions and split the countries and regions into 5 SDI regions based on the spectrum of development: high, high-middle, middle, low-middle, and low. In addition, they separated their included individuals into 6 age groups: 60 to 64 years, 65 to 69 years, 70 to 74 years, 75 to 79 years, 80 to 84 years, and 85 to 89 years. The investigators also assessed potential risk factors for an association with AML.

The analysis revealed that incidence, incidence rate, mortality, mortality rate, DALYs, and mortality rate of older patients in high SDI regions were significantly higher than other SDI regions. Moreover, the incidence rate in high SDI index regions showed a substantial annual increase, with an EAPC of 1.36 (95% CI, 1.24-1.48), while the mortality rate exhibited an upward trend, with an EAPC of 1.12 (95% CI, 1.04-1.19), and the DALYS rate showed a moderate rise with an EAPC of 0.94 (95% CI, 0.85-1.04).

Further, the middle SDI region demonstrated the highest increases in incidence, mortality, and DALYs compared with the other regions; incidence showed an “impressive” increase of 2.54 (95% uncertainty interval [UI], 1.94-3.33), mortality experienced a substantial rise of 2.46 (95% UI, 1.85-3.24), and DALYs showed a notable increase of 2.33 (95% UI, 1.74-3.08). The low SDI region had the lowest incidence, mortality, and DALYs.

Among the geographical regions and countries, the investigators found the following results:

• In 2019, Western Europe had the highest incidence, deaths, and DALYs with 17,298 cases; 14,026 deaths; and 237,146, respectively
• In 2019, North America had the highest incidence rate, with 16.49 cases per 100,000 population
• In 2019, Australia had the highest death rate, with 15.19 deaths per 100,000 population
• From 1990 to 2019, the Andean Latin America region saw the most significant increases in incidence, death, and DALYs rates, with increases of 4.02, 3.73, 3.54 respectively

They also noted that in 1990, the 65-to-69 age group had the highest incidence and deaths. In 2019, however, the 70-to-74 age group had the highest numbers. The 85-to-89 age group had the lowest numbers for incidence, death, and DALYs in 2019, but had the highest rates per 100,000 population for incidence, mortality, and DALYs. Across all age groups, men had higher rates for incidence, mortality, and DALYs than women.

The analysis further explored potential risk factors for AML-related deaths. Based on 2019 data, smoking, high body mass index, occupational exposure to benzene, and occupational exposure to formaldehyde were identified globally as major risk factors.

“These findings were crucial in the development of targeted prevention strategies,” the investigators said.

Overall, their results reveal that incidence, mortality, and DALYs rates showed a continuous upward trend over the 30-year period, largely driven by population aging. Furthermore, increases were strongly correlated with SDI region. The researchers said this finding could be attributed to better health care measures and diagnostic technologies, leading to increased diagnoses and consequently higher incidence and mortality rates.

The authors acknowledged limitations. The Global Burden of Disease database may not have comprehensively covered specific populations, such as ethnic minorities or certain occupational cohorts. In addition, data quality and comprehensiveness may have varied by country. Still, they believe the study focuses attention on an increasingly serious global health issue.

“As the global SDI continued to rise, the importance of AML in older people became increasingly pronounced, especially in high SDI regions,” the authors concluded. “We should have paid more attention.”

Reference

Chen P, Liu X, Zhao Y, Hu Y, et al. Global, national, and regional burden of acute myeloid leukemia among 60 – 89 years-old individuals: insights from a study covering the period 1990 to 2019. Front Public Health. Published online January 11, 2024. doi:10.3389/fpubh.2023.1329529