A 17-year experience with ALL-BFM protocol in acute lymphoblastic leukemia: prognostic predictors and interruptions...

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer and despite the intense combination chemotherapy, cure rates are less than 90%. Several prognostic parameters, including nonneoplastic hematologic cell counts during induction phase, are suggested to predict outcome in ALL. We analyzed 242 ALL patients treated in our center to investigate individual prognostic parameters and the impact of delays on disease outcome. Age at diagnosis, risk groups, extramedullary involvement, t(9;22), prednisone response, bone marrow response at days 15 and 33, day 15 platelet count, day 33 lymphocyte, monocyte, and platelet counts, treatment delay, sepsis, and omission of day 64 cyclophosphamide were valuable predictors of survival in univariate analysis. However only the age, CNS involvement, omission of cyclophosphamide, and total delay during treatment were associated with survival in multivariate analysis. Omission of second cyclophosphamide dose had no impact on survival of standard risk group patients, but adversely affected the long term survival of medium risk group (MRG) patients. The second dose might be given with the first dose on day 36 to MRG patients to prevent delays. Day 15 and 33 platelet counts are promising predictors of survival in low income countries where assessment of minimal residual disease is difficult, but this data needs further consolidation.