ACUTE MYELOID-LEUKEMIA WITH TRANSLOCATION (8-21) - CYTOMORPHOLOGY, DYSPLASIA AND PROGNOSTIC FACTORS IN 41 CASES

The translocation t(8;21) is one of the most common structural aberrat ions in acute myeloid leukemia (AML). Excellent response rates and a b etter relapse-free survival have been described, We analyzed specific morphologic and cytochemical features including dysplasia and other pr ognostic factors in 41 patients with AML and t(8;21) who underwent agg ressive chemotherapy in two national cooperative group studies. Five p atients were classified as AML M1 and 36 as AML M2 according to the FA B criteria. Auer rods were detected in 28 patients (68%), however in o nly 16 patients were they ''thin and elongated'' as has been described as typical for t(8;21). The presence or absence of Auer rods did not appear to be associated with disease-free survival in this sample. Dys granulopoiesis was detected in 31/41 patients (90%); five of these pat ients additionally had dyserythropoiesis (12%). In six cases (15%), dy smegakaryopoiesis was seen in combination with dysgranulopoiesis. Only one patient had trilineage dysplasia. Dysplastic features had no infl uence on prognosis. Additional cytogenetic abnormalities were detected in 24/41 patients. Twelve male (48%) and four female (25%) had a loss of a sex chromosome. This was correlated with a better disease-free s urvival (p = 0.039). The complete remission rate (CR) to chemotherapy was 90%. The early death rate was 10%. Disease-free survival of the co mplete responders was 60% at two years with no relapses observed in te n patients with 2-6 years of follow up. This favorable disease free su rvival was observed with a variety of post-induction regimens and t(8; 21) had been detected as an independent factor for good prognosis. The need for very intensive therapy, such as bone marrow transplantation, is unanswered at this time.