ALL-TRANS-RETINOIC ACID AND LOW-DOSE CYTOSINE-ARABINOSIDE FOR THE TREATMENT OF POOR-PROGNOSIS ACUTE MYELOID-LEUKEMIA

Thirty-three patients with 'poor prognosis' acute myeloid leukemia, no longer suitable for aggressive chemotherapy, were treated with daily oral all-trans retinoic acid (45 mg/m(2)) daily and subcutaneous cytos ine arabinoside (20 mg standard dose twice a day, day 1 to 10, every 4 weeks). Seventeen patients were males and 16 females, the median age was 67 (range 39-82 years). Eleven patients were at onset of disease, 15 were refractory to previous conventional therapies, three were in f irst relapse and three in second relapse and one patient had a seconda ry AML. Seventeen patients had a bone marrow blast infiltration <50% a nd 16 greater than or equal to 50%. A total of 16 (48%) patients enter ed complete remission; the rate of complete remission increased to 88% in those patients (n = 17) with <50% blast infiltration at the time o f entering the study. Seventeen patients (52%) were resistant. The dif ference in response to therapy, according to bone marrow blast percent age (< or greater than or equal to 50%), was statistically significant (P <0.001). Median duration of complete remission was 34.4 weeks (ran ge 6.4-62.8). Mild to moderate hematologic toxicity was the most commo n side-effect. In conclusion all-trans retinoic acid and low-dose cyto sine arabinoside appears to be an effective regimen for inducing compl ete remission in 'poor prognosis' acute myeloid leukemia and patients with <50% bone marrow infiltration are likely to represent the ideal t arget to receive this combination therapy.