Blood counts at time of complete remission provide additional independent prognostic information in acute myeloid leukemia

Prognostic relevance of blood counts at complete remission (CR) in acute myeloid leukemia (AML) is not clear. To address this issue, we analyzed 891 AML patients in first CR. From the data of randomly selected 446 patients (training set), we first established optimal cutoffs for neutrophil and platelet counts and hemoglobin level at CR in terms of relapse-free survival (RFS). Patients whose counts were higher than each optimal cutoff were shown to have significantly better RFS (p < 0.01 for neutrophil and platelets, and p = 0.02 for hemoglobin). Then we tested whether these cutoffs were, after accounting for better known prognostic covariates, also predictive of RFS in the remaining 445 patients (validation set). Our data revealed that higher neutrophil count was independently predictive of longer RFS in the validation set (hazard ratio 1.38, p = 0.02), as was higher platelet count (hazard ratio 1.35, p = 0.04). These findings suggest that blood counts at CR, information readily available, are useful in prognostication in AML.