Acute lymphoblastic leukemia: an assessment of international incidence, survival, and disease burden

Acute lymphoblastic leukemia (ALL) is a rare hematological malignancy. With the recent introduction of a classification system for hematopoietic and lymphoid neoplasms, more comprehensive assessment of ALL epidemiology is now possible. In this study, we describe recent international incidence of ALL and project the annual number of diagnoses to 2025. We also estimate relative survival and average potential years of life lost (AYLL) to assess the societal burden of ALL.

Age-specific incidence data for ALL from select cancer registries in different geographies were obtained from the International Agency for Research on Cancer's Cancer Incidence in Five Continents Database. Country-specific age-standardized rates were calculated to allow for direct comparisons between countries. ALL-specific mortality and relative survival data were only available from the United States (US) National Cancer Institute's Surveillance, Epidemiology, and End Results program; mortality rates were estimated for other countries.

The age-standardized incidence rate of ALL during 2003-2007 ranged from 1.08 to 2.12 per 100,000 person-years in selected countries. Incidence was generally higher in the Americas and Oceania and lower in Asia and Eastern Europe. In most countries, the incidence rate of ALL in children was approximately four times that in adults. Survival was particularly poor among adults. In selected countries, the estimated AYLL ranged from 30 to 48 years for all ages and from 23 to 39 years for adults.

Although a rare disease, ALL presents a significant public health burden given poor survival outcomes among adults, AYLL, and its importance as the most common pediatric cancer.