Relationship between white blood cell count elevation and clinical response after G-CSF priming chemotherapy for acute myeloid leukemia.

We retrospectively analyzed the relationship between white blood cell (WBC) count elevation after priming and clinical response in 115 patients with AML (61 untreated and 54 relapsed or refractory) treated with low-dose cytarabine, aclarubicin, and G-CSF priming. Receiver operating characteristic curve analysis showed that the ratio of maximum WBC count to pretreatment WBC count (WBCratio) was most strongly associated with complete remission (CR) in previously untreated patients among several parameters we analyzed in this study; however, the prediction accuracy was not clinically significant considering the area under the curve of 0.694. Based on the cutoff value of the WBCratio, CR rate and event-free survival in the high WBCratio group were significantly better than those in the low WBCratio group in untreated patients. Regarding the WBC differential counts, a high ratio of the maximum to pretreatment value of neutrophils rather than that of peripheral blasts was associated with a superior CR rate. In addition, an increase in blasts after G-CSF priming had a significant negative impact on CR rate in untreated patients. In conclusion, an increase in blast counts after G-CSF priming was not predictive of achieving CR.