MYELOID LEUKEMIAS AND MYELODYSPLASTIC SYNDROMES - CHEMICAL-EXPOSURE, HISTOLOGIC SUBTYPE AND CYTOGENETICS IN A CASE-CONTROL STUDY

We conducted a case control study of 50 acute myeloid leukemias (AML), 17 chronic myeloid leukemias (CML), 19 myelodysplastic syndromes (MDS ), and 246 controls. The cases were classified according to the French -American-British (FAB) classification, and chromosome aberrations wer e recorded according to the International System for Human Cytogenetic Nomenclature. Exposure to suspected leukemogenic agents was assessed blindly by an industrial hygienist. Increased risks were noted for mec hanics, welders, electricians, and drivers among men and among farmers and textile workers among women. Increased SMRs for leukemias in a ce nsus-based cohort study conducted in the same area (Torino) were previ ously reported for electricians and drivers among men and for textile workers among women. We detected nonstatistically significant increase d relative risks for exposure to benzene (odds ratio, OR = 1.7), petro l refining products (1.9), polycyclic aromatic hydrocarbons (1.7), and electromagnetic fields (1.6) in men; in women, a statistically signif icant association with exposure to pesticides was detected [OR = 4.4; 95% confidence interval (CI) 1.7-11.5]. Although exposure to pesticide s was confined to AML, MDS cases included a high proportion of subject s exposed to benzene and electromagnetic fields. No particular histolo gic subtype of AML was associated with chemical exposures except for t hat of pesticides with the M4 category. Chromosome aberrations were no t associated with chemical exposures (OR = 1.0), but a nonstatisticall y significant excess was noted in association with electromagnetic fie lds (OR = 2.1).