Empirical examination of the neutrophil criterion (>1500 μl^-1) currently needed to declare CR in AML

Currently, NCI guidelines require that the neutrophil count exceed 1500 before complete remission (CR) may be declared in acute myeloid leukemia (AML). We tested the empirical validity of this formulation by comparing event-free survival (EFS) in CR in (a) 305 patients who met the NCI criteria for CR and (b) 36 patients who met all the criteria for CR except that the neutrophil count at what we considered CR was 1000-1499 (lower neutrophil group) at which time they began post-remission therapy. EFS was statistically identical in both groups. We extended these findings to 752 patients, who met the NCI criteria for CR except that some may have had circulating blasts at "CR"; 82 of the 752 were in the lower neutrophil group. These data suggest that the minimum needed to declare CR in AML be changed from 1500 to 1000.