Correlation of karyotype with clinical features in acute lymphoblastic leukemia.

We studied the clinical and karyotypic features of 50 patients with acute lymphoblastic leukemia, including 33 American and 17 Japanese patients, at two institutions. Clonal chromosome abnormalities were found in 39 of the 50 patients (78%) at diagnosis. Eleven patients had diploidy (N patients). Among the 39 aneuploid patients, 17 had pseudodiploidy (A1 patients), eight had hyperdiploidy with 47 to 49 chromosomes (A2 patients), nine had hyperdiploidy with 50 to 59 chromosomes (A3 patients), and five had other chromosome abnormalities. Of 14 patients whose chromosomes were also studied at relapse, eight had karyotypic progression, five had abnormalities identical or similar to those observed at diagnosis, and one had a change of karyotype from diploidy to aneuploidy. The median age and the median WBC of A1 patients were higher than those of any other group of patients, although one-third of the patients had WBC below 20 x 10(3)/microliters, and they often had leukemic cells of T-cell or B-cell lineage. The A2 patients were relatively old and tended to have higher WBC. The N patients were relatively young and tended to have low WBC, although these tendencies were not as marked as those in A3 patients. The A3 patients had longer survival times than the A1 (p = 0.003) or A2 (p = 0.002) patients. Also, N patients had longer survival times than A1 (p = 0.03) or A2 (p = 0.05) patients. The difference in survival times between A3 and N patients was not significant. Our study demonstrated that the karyotype is correlated with survival and with other recognized prognostic factors. However, in some A1 and A2 patients, the karyotype was a more reliable factor in indicating a poor prognosis than was the WBC or age.