Causes of initial remission induction failure in patients with acute myeloid leukemia and myelodysplastic syndromes.

We analyzed 144 of 475 previously untreated patients with acute myeloid leukemia (AML, n = 87) and 'high-risk' myelodysplastic syndromes (MDS, n = 57) who failed to achieve a complete remission with fludarabine- and high-dose cytarabine-containing regimens between 1991 and 1994. The AML and MDS groups were comparable with regard to age, major prognostic indicators, supportive care received, type of antileukemia response and causes of death and were considered together. The causes of death of 118 evaluable patients were compared to a series of 123 AML initial remission induction failures previously reported from our institution. The induction failure rate was significantly lower (30 vs 43% P <0.001). We found a significant decrease in fatal infections (autopsied patients, P = 0.001) and a reduction in bacterial (autopsied and non-autopsied patients, P <0.005) but not fungal (non-autopsied patients, P = 0.93; autopsied patients P = 0.15) infections as causes of induction death. Pulmonary hemorrhage was twice as common in the present report (P < 0.005, with pulmonary hemorrhage almost three times as common as fatal cerebral hemorrhage. A comparison restricted to the AML patients in the present study yielded similar results. We conclude that the mortality profile in AML remission induction has undergone substantial changes at our institution since our last report, probably as a consequence of the introduction of new chemotherapy regimens and supportive care modalities.