Global Burden of CLL Decreasing, But Key Challenges Remain

The global burden of chronic lymphocytic leukemia (CLL) has decreased over the past 30 years, according to a new analysis. However, the authors of the new report published in Cancer Control noted that the burden and trends vary significantly from region to region.

The study emphasized the need for tailored strategies to address the burden of CLL globally. | Image credit: sovova - stock.adobe.com

CLL is the most common type of leukemia among adults, making up between one quarter and one third of all leukemia cases.2 Despite its prominence, there has been insufficient research into the global burden of the disease, the authors explained. Such research is particularly important considering widespread use of new therapies such as Bruton tyrosine kinase inhibitors, BCL-2 inhibitors, and anti-CD20 monoclonal antibodies.

The investigators turned to the Global Burden of Disease 2021 study, which provides data on hundreds of diseases in 204 countries and regions.3 They then compared 2021 data to data from 1990 in several disease-burden categories.1

The report showed that there were 117,987 new cases of CLL reported worldwide in 2021, which represents a 103% increase since 1990, the authors said. However, the age-standardized rate for incidence from 1990 to 2021 had a downward trend (estimated annual percentage change [EAPC]: –0.47; 95% CI, –0.67 to –0.28). But the incidence change varied by region. Regions with high social development index (SDI) scores saw decreases, low-SDI regions saw stable incidences, and other regions saw increases.

In terms of global prevalence, an estimated 721,066 people had CLL in 2021, and the age-standardized rate was 8.34 cases per 100,000 people (95% CI, 6.94-9.40). The EAPC was stable overall (0.15; 95% CI, –0.11 to 0.40). High-SDI regions saw a decreasing trend, while other regions saw increases.

A total of 45,573 people died from CLL in 2021, but while Western Europe reported the highest number of deaths, only low-middle SDI regions saw an upward trend in mortality, the authors noted. Disability-adjusted life years (DALYs) also had a downward trend (EAPC: –1.52; 95% CI, –1.63 to –1.40).

“Our findings reveal an overall decline in the global CLL burden over the past 3 decades, although certain regions and countries continue to experience increasing trends,” the authors wrote.

The authors also noted that high-SDI regions still have a heavier CLL burden. They posited that the high CLL burden may be due to epidemiological factors, such as broader cancer registry coverage and advanced diagnostic techniques. They added that aging populations in high-SDI countries and genetic factors also likely contribute to the high burden.

Differences in resources also have significant effects on patient outcomes, and the high cost of treatment and limited accessibility of newer therapies have created significant inequalities in CLL treatment worldwide.

“These disparities underscore the urgent need for targeted interventions and the allocation of resources in resource-limited settings to address the growing burden of CLL,” the authors wrote.

The analysis also found that men have a higher CLL burden than women, confirming trends seen in other studies. In terms of risk factors, smoking emerged as an important risk factor. The authors noted that a clear association between tobacco use and CLL has not been established, but they added that smoking consistently appears as a potential risk factor for CLL in studies of disease burden. “Thus tobacco control remains an important preventative measure against CLL, and global efforts to reduce smoking rates should be intensified,” the authors wrote.

The study overall emphasized the need for tailored strategies to address the burden of CLL globally.

“These findings underscore the need for region- and population-specific strategies. Priorities include improving access to novel therapies in high-SDI regions, strengthening primary care and exposure prevention in low- and middle-SDI regions, and tailoring interventions to the elderly population to address the impact of aging.

References

1. Chen C, Wang L, Du S, Qiu Y, Liu Y, Teng Q. Global burden of chronic lymphocytic leukemia from 1990 to 2021. Cancer Control. 2025;32:10732748251397071. doi:10.1177/10732748251397071
2. Kobayashi BI, Dias LB, Achermann VC. Chronic Lymphoid Leukemia: a systematic review of its epidemiological, etiological and genetic aspects. Brazilian Journal of Health Review. 2023;6(5):26068-26078. doi:10.34119/bjhrv6n5-325.
3. GBD 2021 Diseases and Injuries Collaborators. Global incidence, prevalence, years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE) for 371 diseases and injuries in 204 countries and territories and 811 subnational locations, 1990-2021: a systematic analysis for the Global Burden of Disease Study 2021. Lancet. 2024;403(10440):2133-2161. doi:10.1016/S0140-6736(24)00757-8