Prognostic value of cytologic parameters in acute myelogenous leukemia

The prognostic value of some current cytologic characteristics was assessed in 174 adult patients with acute myelogenous leukemia (AML) treated according to the AML-5 protocol of the EORTC Leukemia and Hematosarcomas Group. A significantly higher rate of complete remission (CR) was observed in patients with low bone-marrow (BM) cellularity, with BM blasts less than 80%, and with Auer rod positive cells more than 2.5% of the total blast cell population. A leukocyte count of less than 50 X 10(9)/1 in the peripheral blood was also associated with a higher CR rate. No significant difference was found between the various French-American-British (FAB) subtypes, in spite of a trend towards a lower CR rate in patients with an M1, myeloblastic, poorly differentiated, subtype. The leukocyte count and the percentage of Auer rod positive cells were the only significant parameters for duration of survival from the beginning of maintenance treatment. However these features had no prognostic value for the duration of remission. It seems therefore that patients with a higher percentage of Auer-rod-positive cells and lower peripheral leukocyte counts can enter remission more easily, and can also more readily achieve subsequent remissions following relapse. The prognostic value of these routine cytologic features is probably related to their relationship with proliferative activity and tumor burden: the percentage of Auer-rod-positive cells correlates inversely with the leukocyte count, whereas leukocyte count, BM cellularity, and percentage of BM blasts are linked together.