Purpose: Studies evaluating adolescent risk factors for developing acute myeloid leukemia (AML) are virtually nonexistent. We assessed adolescent predictors of AML in adults, with a main focus on adolescent BMI.
Methods: The study included 2,310,922 16-19-year-old Jewish Israeli adolescents (mean age 17.3 ± 0.4, 59.5% male), called up for an obligatory health examination. Sociodemographic and health data, including measured weight and height, were gathered. Body mass index (BMI) was examined both as a continuous variable and grouped according to the World Health Organization (WHO) classification and US-CDC percentiles. Bone-marrow-biopsy-verified AML cases diagnosed up to 31 December 2012 were identified by linkage to the Israel national cancer registry. Multivariable-adjusted Cox proportional-hazards models were used to model time to diagnosis.
Results: During 47 million person years of follow-up, 568 AML cases were identified (crude incidence rate 1.21/100,000 person years). There was a multivariable-adjusted hazard ratio (HR) of 1.041 (95% CI 1.015-1.068, p = 0.002) per unit BMI. The association was evident in those of Middle Eastern, North African, and European origin. A graded association was evident across the overweight and obese WHO grouping. With the US-CDC grouping, excess risk was evident in overweight but not in obese adolescents, although a test for trend in percentiles was significant (p = 0.004). Borderline associations were noted for origin (p = 0.065) (higher in the predominantly Ashkenazi European origin), sex (higher in women: HR = 1.24 (95% CI 0.99-1.55), and stature (HR = 1.013, 95% CI 1.000-1.026, per cm).
Conclusions: Higher BMI in adolescence was associated with increased AML incidence in adulthood in this multiethnic population.
Keywords: Acute myeloid leukemia; Adolescence; Ashkenazi; Body mass index; Ethnicity; Middle East; North Africa; Risk factors; Western Asia.