Analysis of epidemiological characteristics of leukemia in Kazakhstan using unified nationwide electronic healthcare data

Background: Leukemia is the fifth leading cause of cancer mortality worldwide. Based on the rate of cellular division, leukemia is classified into acute or chronic myeloid or lymphoid types. Previous studies have highlighted rising leukemia cases in Kazakhstan; however, no study has described the epidemiology of leukemia and its subtypes. Methods: This retrospective cohort study uses the unified nationwide electronic healthcare system to characterize the epidemiology of leukemia and its subtypes in patients treated in any clinical setting in Kazakhstan from 2014 to 2019. The Chi-square test was used for categorical variables, the independent t-tests for continuous numeric variables between two groups, and ANOVA for comparing means across multiple groups. A cox proportional hazards regression model calculates crude and adjusted hazard ratios for all-cause mortality risk. Results: Of 9,561 patients, 4,783 (50.1%) were male and 4,778 (49.9%) were female. Median survival was 12 years (4,508 days). Mortality rates varied, with a slight increase in unspecified leukemia (C95) diagnoses in 2018-2019. Males (HR = 1.15, [95% CI: 1.07-1.23]), urban residents (HR = 1.52, [95% CI: 1.40-1.65]), and older individuals had higher mortality risks. Russians (HR = 1.42, [95% CI: 1.28-1.57]) and patients with hypertension (HR = 1.58, [95% CI: 1.53-1.64]) or chronic kidney disease (HR = 1.84, [95% CI: 1.60-2.10]) faced higher risk of death. Conclusion: Leukemia incidence and mortality in Kazakhstan are higher among males, urban residents, older individuals, and patients with comorbidities. These findings highlight the need for targeted healthcare policies and clinical management strategies to address disparities and improve outcomes in Kazakhstan.