In acute myeloid leukemia (AML) patients, a variety of clinical and biologi
c parameters, including phenotype, have been examined for potential value i
n predicting treatment response and survival. The European Group for the Im
munological Classification of Leukaemias (EGIL) has proposed that AML be de
fined immunologically by the expression of 2 or more of the following myelo
id markers: myeloperoxidase, CD13, CD33, CDw65, and CD117, With regard to t
his classification, the prognostic significance of 21 antigens taken separa
tely and with immunophenotypic subgroups were evaluated and compared with o
ther clinical and biological variables in 177 adult AML patients. None of t
he antigens tested were associated with treatment outcome. In contrast, pat
ients with blasts disclosing a full expression of panmyeloid phenotype (def
ined by the expression of all 5 myeloid markers) had a higher complete remi
ssion rate (P < .0001) and differed significantly in disease-free survival
(P = .02) and overall survival (P = .008) than patients whose cells express
ed fewer than 5 of these markers. In multivariate analysis, only age, panmy
eloid phenotype, performance status, and permeability glycoprotein activity
influence treatment outcome, Cyto genetics was significant in univariate a
nalysis but not in multivariate analysis, most likely because of the redund
ancy with panmyeloid phenotype and a higher sensitivity of immunophenotypin
g, Patients whose cells exhibit the panmyeloid phenotype appear to define a
relatively homogeneous biological subset of AML, The 4 independent prognos
tic factors were used to create a prognostic score, defined by the number o
f factors present. This score permitted a stratification of patients with A
ML, thereby allowing for the consideration of innovative therapies to impro
ve outcome in the poorer outcome groups, (C) 2000 by The American Society o
f Hematology.