Are Incidence rates of adult leukemia in the United States significantly associated with birth cohort?
A partir des données des registres américains des cancers portant sur la période 1992-2009 et incluant des adultes âgés de 25 à 84 ans, cette étude analyse l'évolution de l'incidence de leucémie chez l'adulte en fonction de l'année de naissance
BACKGROUND: Leukemia is a common cancer among United States adults but there are few established risk factors. If leukemia risks are substantially influenced by exposures that vary in prevalence across generations, then population incidence rates should vary significantly by birth cohort. However, prior studies have not examined leukemia birth cohort effects using contemporary data and methods. METHODS: We used incidence data from the National Cancer Institute's Surveillance, Epidemiology and End Results Program from 1992 through 2009 for adults 25 - 84 years old and age-period-cohort models to estimate incidence rate ratios according to birth cohort for acute myeloid leukemia (AML), acute lymphoid leukemia (ALL), chronic myeloid leukemia (CML), and chronic lymphoid leukemia (CLL). RESULTS: Leukemia incidence varied significantly between birth cohorts for each major leukemia type in men and women except female AML; changes on the order of 1% per birth year or 20% per generation were observed. The most significant birth cohort signatures were observed for CLL and AML in men, which were decreasing and increasing, respectively, in cohorts born since 1946. CONCLUSIONS: Our results support the hypothesis that adult leukemia risks are significantly modulated by environmental and lifestyle exposures. IMPACT: A number of well-established (smoking, certain chemicals, radiation) and newly-recognized (obesity) leukemia risk factors are modifiable; ultimately, efforts to promote healthy lifestyles might also help reduce incidence rates of adult leukemia.