Longitudinal analysis of incidence, mortality, and survival trends in acute lymphoblastic leukemia: A five-decade study with insights into demographic disparities from Surveillance, Epidemiology and End Results program database (1975-2021).

Abstract

e18530 Background: Acute lymphoblastic Leukemia (ALL) is a rare malignancy accounting for 0.3% of all new cancer cases and 0.2% of cancer-related deaths in the U.S. While significant improvements in survival rates have been observed over time, gender- and ethnicity-based disparities persist, underscoring the need for further investigation into these trends. This study examines trends in incidence, mortality, and 5-year relative survival rates for ALL between 1975 and 2021, using SEER registry data and U.S. mortality statistics. Disparities by gender, ethnicity, and age groups are specifically analyzed. Methods: This was a population-based retrospective cohort study conducted using data from SEER database. Age-adjusted rates for new cases, deaths, and 5-year relative survival were obtained from SEER 8, SEER 12, and national mortality databases. Observed rates were compared with modeled trends, and demographic stratification was applied to assess disparities. Results: The incidence of ALL rose from 1.07 per 100,000 in 1975 to 1.62 per 100,000 in 2021 (p < 0.001). Males consistently had higher rates than females (2.1 vs. 1.6 per 100,000, p = 0.02), with Hispanic males showing the highest rates (3.0 per 100,000, p < 0.001), and non-Hispanic Black males the lowest (1.1 per 100,000). Non-Hispanic White males had a higher incidence than non-Hispanic Black males (1.8 vs. 1.1 per 100,000, p < 0.01) but lower than Hispanic males (p < 0.001). Mortality rates declined from 0.66 per 100,000 in 1975 to 0.43 per 100,000 in 2021 (p = 0.04), but disparities remained, with Hispanic males having higher mortality rates (0.7 per 100,000) compared to non-Hispanic Black males and females (0.3 per 100,000, p < 0.01). The highest percentage of deaths occurred in individuals aged 65-74 (18.3%, p < 0.01). Non-Hispanic Whites had lower mortality rates than Hispanics (0.5 vs. 0.7 per 100,000, p = 0.03). The 5-year relative survival rate improved from 30.69% in 1975 to 77.62% in 2016 (p < 0.001), with younger patients (<20 years old) showing better survival outcomes than older adults (p < 0.001). However, disparities persisted, as Hispanic and non-Hispanic Black populations had lower survival rates compared to non-Hispanic Whites (p < 0.01). Conclusions: This longitudinal analysis demonstrates substantial progress in reducing mortality and improving survival outcomes for ALL over five decades. Nonetheless, significant disparities remain in incidence, mortality, and survival across gender and ethnic groups. Focused interventions are required to bridge these gaps and achieve equitable outcomes for all populations.