Occupational history and involvement of chromosomes 5 and 7 in acute nonlymphocytic leukemia.

We compared the histories of exposure to leukemogens for two groups of patients presenting with myelodysplastic syndrome (MDS) or acute nonlymphocytic leukemia (ANLL). In one group there were 59 patients with an acquired abnormality of chromosomes 5 or 7 in the marrow at time of diagnosis. In the other group there were 39 patients with a normal marrow karyotype at the time of diagnosis. A much higher proportion of the chromosomally abnormal cases had a history of treatment for a previous malignancy (odds ratio = 13.0, p less than 0.01). There was little difference found between the occupational histories of the patients with de novo ANLL with and without cytogenetic abnormalities. An occupational history of exposure to chemicals or metals was more common in males with either a deletion of the long arm of chromosome 7 or with monosomy 7 or monosomy 5 (82.3%) than in males with a normal karyotype (52.1%). The odds ratios did not, however, reach statistical significance.