Cytogenetic abnormalities in the myelodysplastic syndromes and occupational or environmental exposure

Patients with myelodysplastic syndromes (MDS) have high frequencies of cytogenetic abnormalities and evidence is accumulating of associations between exposure history and primary MDS, The objective of this article is to examine the relationship between histories of occupational or environmental exposure and presence of cytogenetic abnormalities. A case control study of MDS patients estimated lifetime exposure to more than 90 potential hazards in 400 age, sex, and area of residence matched patient and control pairs. A parallel cytogenetics study undertaken at time of diagnosis, independently of any knowledge of exposure history, identified 75 cytogenetically abnormal and 139 normal (186 not studied). Odds ratios of MDS patients and their matched controls were compared for 3 groups: cytogenetically abnormal, normal, and not known. The odds ratios for all exposures combined were possibly higher among cytogenetically abnormal 2.0 (95% confidence interval 0.8-5.9) than among normal 1.0 (0.6-1.8). This pattern was observed for exposure to semimetals, abnormal 4.0 (0.4-195.1) and normal 0.5 (0.1-1.0) and inorganic dusts, 1.6 (0.6-3.8) and 0.4 (0.1-1.4) respectively. The pattern was principally in abnormalities in chromosomes 5 and 7. For organic chemicals and radiation, the odds ratios for both cytogenetically abnormal and normal were marginally raised: organic 1.8 (0.6-6.0) and 1.3 (0.6-2.9), respectively, and radiation 1.7 (0.5-5.6) and 1.3 (0.4-4.7) respectively. For radiation, abnormalities were mostly in chromosome 8. This study of association between exposures and cytogenetics in primary MDS complements those previously reported in secondary MDS and may provide some insight into pathogenetic mechanisms that lead to development of MDS. (C) 2000 by The American Society of Hematology.