Cytogenetic studies in 18 patients with secondary blood disorders.

Cytogenetic studies were carried out in 18 patients with secondary blood diseases; 15 patients had a history of prior malignancy, two had been professionally exposed to carcinogenic agents, and one patient had been treated with immunodepressors. The interval between initial therapy and secondary disease ranged from 13 to 123 months, with a mean of 57.8 months; the mean survival time from the diagnosis of secondary disease was 6 months. Cytogenetic abnormalities were present in 83% of cases, with a trend to hypodiploidy in 90%. The most often involved chromosomes were #5, #7, and 3p. A correlation between the cytogenetic abnormalities and etiologic factors has been analyzed; data from the present series and from the literature suggest a correlation between chromosome #7 and chemical agents, and chromosomes #11, #12, and #17 and physical agents.