Acute leukemia in adults: assessment of remission induction with combination chemotherapy by clinical and cell-culture criteria.

Remission induction was assessed by clinical and cell-culture criteria for 65 patients with acute myelogenous leukemia (AML), 11 patients with chronic myelogenous leukemia (CML) in blast crisis and 19 patients with acute lymphoblastic leukemia (ALL). Cyclophosphamide, cytosine arabinoside and vincristine (CAV) therapy resulted in complete remission in 23 of 50 previously untreated patients with AML and in 3 of the 11 patients with CML. Fourteen patients with ALL responded to vincristine-prednisone induction therapy and two to induction therapy with CAV. The median duration of survival of the responding patients was 2.2 years, compared with 4 months for the patients who did not respond to treatment. Granulopoietic colony formation, assessed by assay of colony-forming units dependent on colony-stimulating activity in culture (CFU-C), was abnormal in 37 of 42 bone marrow aspirates from patients with AML before treatement. CFU-C concentration increased when leukocyte-conditioned medium (LCM) was added to the cultures; 13 cultures had normal or elevated CFU-C concentration with LCM. Marrow cells of patients with ALL or CML in blast crisis demonstrated a similar pattern. Serial studies of marrow CFU-C concentration of 31 patients with AML demonstrated a change to a normal pattern with successful remission induction. Results of this study suggest that administration of purified LCM to leukemic patients might increase granulocyte production from potential but unstimulated granulopoietic precursors. This therapy would lessen the probability of death from infection during remission induction.