Adult leukemia survival trends in the United States by subtype: A population-based registry study of 370,994 patients diagnosed during 1995-2009

Abstract

Background: The lifetime risk of developing leukemia in the United States is 1.5%. There are challenges in the estimation of population-based survival using registry data because treatments and prognosis vary greatly by subtype. The objective of the current study was to determine leukemia survival estimates in the United States from 1995 to 2009 according to subtype, sex, geographical area, and race.

Methods: Five-year net survival was estimated using data for 370,994 patients from 43 registries in 37 states and in 6 metropolitan areas, covering approximately 81% of the adult (15-99 years) US population. Leukemia was categorized according to principal subtype (chronic lymphocytic leukemia, acute myeloid leukemia, and acute lymphocytic leukemia), and subcategorized in accordance with the HAEMACARE protocol. We analyzed age-standardized 5-year net survival by calendar period (1995-1999, 2000-2004, and 2005-2009), leukemia subtype, sex, race, and US state.

Results: The age-standardized 5-year net survival estimates increased from 45.0% for patients diagnosed during 1995-1999 to 49.0% for those diagnosed during 2000-2004 and 52.0% for those diagnosed during 2005-2009. For patients diagnosed during 2005-2009, 5-year survival was 18.2% (95% confidence interval [95% CI], 17.8%-18.6%) for acute myeloid leukemia, 44.0% (95% CI, 43.2%-44.8%) for acute lymphocytic leukemia, and 77.3% (95% CI, 76.9%-77.7%) for chronic lymphocytic leukemia. For nearly all leukemia subtypes, survival declined in successive age groups above 45 to 54 years. Men were found to have slightly lower survival than women; however, this discrepancy was noted to have fallen in successive calendar periods. Net survival was substantially higher in white than black patients in all calendar periods. There were large differences in survival noted between states and metropolitan areas.

Conclusions: Survival from leukemia in US adults improved during 1995-2009. Some geographical differences in survival may be related to access to care. We found disparities in survival by sex and between black and white patients.

Keywords: Epidemiology; National Program of Cancer Registries; Surveillance; United States; and End Results (SEER); cancer; cancer registries; leukemia; population-based survival.