Abnormal/normal metaphase ratio and prognosis in chronic B-lymphocytic leukemia.

Cytogenetic analysis was performed in B-cell mitogen-stimulated leukemic cell cultures from 55 patients with chronic B-lymphocytic leukemia. Clonal chromosomal aberrations were found in the cells of 33 patients, whereas 10 patients were cytogenetically normal. For 12 patients, too few metaphases were found to enable proper evaluation of the karyotype. The patients were subdivided into four groups according to the ratio between the number of metaphases with abnormal and normal chromosome patterns: AA, patients with only abnormal (A) metaphases; A/N high, patients with both abnormal and normal (NN metaphases and an A/N ratio greater than 0.5; A/N low, patients with an A/N ratio less than 0.5; NN, patients with only normal metaphases. In a log rank analysis, increasing A/N ratio was significantly associated with poor survival (p = 0.025). Four AA patients had a median survival of 6 months, whereas the 5-year probability of survival was 0.62 for the A/N high group, 0.92 for the A/N low group, and 1.0 for the NN group.