Kinetics of colony-forming cells (CFU-c) in adult acute leukemia and their prognostic relevance.

The in vitro growth pattern of bone marrow and peripheral blood in soft-agar cultures was studied in 50 previously untreated patients with adult acute leukemia. Patients were followed from time of first diagnosis, during induction treatment, in remission at various time intervals, at relapse and during subsequent re-induction therapy. The distribution of granulopoietic progenitor cells was analysed to determine their prognostic significance for remission incidence, remission duration and survival. All patients revealed an abnormal growth. ANLL patients showing a decreased clone number in the marrow but an increased number of clones in the peripheral blood, had a significant higher probability to enter remission and a significant longer remission than those having clones within normal range at first presentation. On the contrary, ALL patients responding to induction treatment, had a better colony and cluster growth in the bone marrow than those failing to respond. No significant correlation was found between in vitro growth and survival. It is concluded that colony-forming cells of both bone marrow and peripheral blood seems to be of some value in predicting the response rate and length of remission in ANLL and ALL, and in possibly selecting patients with a high chance to respond to current cytostatic regimens.