Myeloid markers in adult acute lymphocytic leukemia. Correlations with patient and disease characteristics and with prognosis.

BACKGROUND: The expression of myeloid markers on lymphoblasts has been associated with adverse outcome in acute lymphocytic leukemia (ALL). The purpose of the study was to analyze the experience with adults treated at the University of Texas M. D. Anderson Cancer Center with myeloid marker- (MY) positive ALL in relation to patient and disease characteristics, response to therapy, and prognosis.

METHODS: Since 1988, 64 of 162 adults (40%) with newly diagnosed ALL referred to our service had MY-positive ALL. Their characteristics and outcomes were compared with the 98 patients with MY-negative ALL. Patients were treated with the vincristine-doxorubicin-dexamethasone (VAD) regimens.

RESULTS: Patients with MY-positive ALL were significantly older (median ages, 47 years vs. 33 years; P = 0.03), had a higher incidence of CD34 antigen expression (59% vs. 36%; P < 0.01), and a lower incidence of common acute leukemia antigen expression (50% vs. 71%; P < 0.01), serum alkaline phosphatase elevation (58% vs. 83%; P < 0.01), and thrombocytopenia at diagnosis (49% vs. 69%; P = 0.02). Myeloid marker positivity, as expected, was significantly higher in null cell ALL (82%), and significantly lower in mature B-cell ALL (17%) (P < 0.01). Forty-one of 64 MY-positive patients achieved complete remission (CR) after induction therapy compared with 76 of 98 patients MY-negative disease (CR rate 64% vs. 78%; P = 0.06). With a median follow-up of 45 months, no statistical differences were observed in remission duration or survival between MY-positive and MY-negative patients, overall, and within immunophenotypic subsets (T-cell vs. others), or among subgroups with single marker (CD13, CD14, CD33, CD34) positivity. The 3-year remission duration rates were 32% for MY-negative and 40% for MY-positive patients (P not significant), and 3-year survival rates were 26% and 31%, respectively (P not significant).

CONCLUSIONS: With VAD therapy, myeloid marker positivity is not associated with significant differences in prognosis in adult ALL.