The prognostic significance of chromosomal analysis and immunophenotyping in 117 patients with de novo acute myeloid leukemia

Chromosomal abnormalities is one of the most important prognostic factors in acute myeloid leukemia (AML). Other parameters which may influence the prognosis include age, French-American-British-type, clinical variables and possibly the expression of certain immunophenotypic surface makers. However, only rarely has the expression of these markers been analyzed in multivariate models including the information from cytogenetics and clinical variables. We conducted a retrospective study of 117 consecutive adult patients with de novo AML diagnosed and treated in our institution during a 6-year period. Following standard induction chemotherapy with daunomycin and cytosine arabinoside 75 patients (64%) achieved complete remission (CR). The overall 5 year survival rate was 23% and, for patients achieving CR, 30%. When all patients were analyzed age, chromosomal aberration and lack of CD33 expression were of independent prognostic value. The overall 5 year survival rate was 28% for patients aged 55 years or younger, 25% for patients aged 56-65 years and 4% for those > 65 years, P = 0.041. Patients with good-risk chromosomal abnormalities presented an overall 5 year survival of 36%, compared to 25% in patients with normal karyotype, 22% in patients with intermediate risk abnormalities and 5% in patients with poor-risk abnormalities, P = 0.004. Patients with CD33+ myeloblasts had an overall survival of 25% at 5 years compared to 0% in the CD33- patients, P = 0.021. Analysis of the expression of CD7, CD34 and terminal deoxynucleotidyl transferase on myeloblasts had no impact on overall survival in a multivariate analysis. Thus, this study confirmed the prognostic value of age and cytogenetic risk group and defined CD33 as a novel factor of independent prognostic importance in adult de novo AML.