Additional chromosome aberrations in acute promyelocytic leukemia: characteristics and prognostic influence

Patients with acute promyelocytic leukemia (APL) show other chromosome aber rations in addition to t(15;17) but their influence on the clinical outcome is still unclear. We have cytogeneticaly analyzed 43 APL patients with t(1 5;17)(q22;q21), treated with all-trans-retinoic acid (ATRA) according to th e recommendations of the European APL 91 Group. Additional chromosome aberr ations were observed in 14/43 patients (33%) studied at initial diagnosis. These patients were designed as 'complex' karyotype group and were compared to patients with t(15;17)as a sole cytogenetic abnormality ('simple' karyo type group). The 'complex' group had significantly lower platelet count and fibrinogen level and fewer cases without significant DIC at diagnosis than the 'simple' group, Comparison of 'simple' and 'complex' groups showed sig nificant difference in complete remission rate (76% vs 35.7%, P = 0.0148) a nd early death rate (24% vs 64.3%, P = 0.0141). Survival analysis showed th at the presence of additional chromosome abnormalities and significant DIC had an adverse effects on prognosis (P = 0.036 and P = 0.041, respectively) , independent on other prognostic factors. These data indicate more aggress ive biological nature of leukemic cells in patients with additional chromos ome aberrations. Supplementary therapeutic strategies may be required for t his subgroup of APL patients.