Prognostic significance of in vitro marrow culture growth pattern in untreated acute nonlymphocytic leukemia.

The growth pattern of marrow cells in agar culture was studied in 90 adult patients with acute nonlymphocytic leukemia (ANLL) at diagnosis. We classified the abnormal growth patterns into 4 groups, A: no growth, B: decreased growth, C: excessive microcluster formation and D: excessive cluster growth with more than 20 colonies. There was a good correlation between growth pattern and FAB subtype. A predominance of group A growth was observed in M1, while group B growth was found in 50% of patients with M2 and M5. No relationships between the growth patterns and other clinical parameters were detected. Sixty-six patients were evaluable for treatment outcome. The growth pattern significantly correlated with complete remission rate. The remission rates were 52, 87, 80, and 25% for patients with group A, B, C and D growth, respectively. Analyses of remission duration and survival curves showed significant differences among the different growth patterns. Patients with D growth experienced a shorter remission duration and a lower survival rate than other groups. These results indicate that the in vitro culture growth pattern in untreated ANLL is of prognostic significance in predicting the response to therapy.