Objectives: To explore MICM classification and adverse prognostic factors in adolescents with acute lymphoblastic leukemia (ALL).
Methods: The MICM classification, clinical characteristics of 80 adolescents with ALL admitted to our hospital from January 1998 to December 2002 were retrospectively analyzed. Survival data were estimated by the Kaplan-Meier method and the prognostic factors were analyzed with the COX regression model.
Results: In the 80 patients, B-ALL and T-ALL accounted for 69.12% and 26.47%, respectively. The percentage of Ph(+)ALL was 18.37% (9/49), and that of hyperdiploidy was 4.08%. Patients at diagnosis with high leukocyte counts (> 50 x 10(9)/L) accounted for 27.94%. Among the 78 cases treated with VDP(L) or CODP(L) regimens, 73 (91.03%) obtained CR in 4 weeks. After a median follow-up of 24 months, the estimated 3-year disease-free survival (DFS) rates of patients receiving chemotherapy or allo-HSCT were (32.55 +/- 16.50)% and (69.58 +/- 8.72)%, respectively (P < 0.05). In COX analysis, high initial leukocyte counts (> 50 x 10(9)/L) and Philadelphia chromosome positivity were adverse prognostic factors for long-term survival.
Conclusions: MICM classification has important clinical and prognostic significance in the risk-directed therapy of adolescents with ALL. The adverse prognostic features for these patients were high leukocyte counts, less incidence of chromosome hyperdiploidy and Ph chromosome positivity.