Cytogenetic abnormalities in the myelodysplastic syndromes and occupational or environmental exposure

Patients with myelodysplastic syndromes (MDS) have high frequencies of cyto genetic abnormalities and evidence is accumulating of associations between exposure history and primary MDS, The objective of this article is to exami ne the relationship between histories of occupational or environmental expo sure 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 pa rallel 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 mat ched controls were compared for 3 groups: cytogenetically abnormal, normal, and not known. The odds ratios for all exposures combined were possibly hi gher among cytogenetically abnormal 2.0 (95% confidence interval 0.8-5.9) t han among normal 1.0 (0.6-1.8). This pattern was observed for exposure to s emimetals, 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 princi pally in abnormalities in chromosomes 5 and 7. For organic chemicals and ra diation, 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, a nd radiation 1.7 (0.5-5.6) and 1.3 (0.4-4.7) respectively. For radiation, a bnormalities were mostly in chromosome 8. This study of association between exposures and cytogenetics in primary MDS complements those previously rep orted in secondary MDS and may provide some insight into pathogenetic mecha nisms that lead to development of MDS. (C) 2000 by The American Society of Hematology.