Long‐term outcomes for unselected patients with acute myeloid leukemia categorized according to the World Health Organization classification: a single‐center experience

Abstract

The actual utility of a new classification system of acute myeloid leukemia (AML) recently introduced by the World Health Organization (WHO) has not been thoroughly investigated yet. In this study, we evaluated long-term outcomes of unselected AML patients categorized according to the new WHO classification. Between 1990 and 2002, 109 adult AML cases were referred to our hospital. For the entire population, the median survival duration was 1.2 yr with a 5-yr survival rate of 31%. AML with recurrent genetic abnormalities accounted for 26%, AML with multilineage dysplasia for 29%, therapy-related AML for 13%, and AML not otherwise categorized for 32% of classifiable cases. Among the four groups, a significant difference was observed in terms of overall survival (P < 0.0001). Univariate analysis showed that six variables affected survival: cytogenetic risk, age, multilineage dysplasia, prior chemo/radiotherapy, type of treatment (intensive or palliative), and transplantation. However, in multivariate analysis no adverse prognostic impact of multilineage dysplasia and prior chemo/radiotherapy was detected (P = 0.4979 and 0.8702), whereas cytogenetic risk and patient age maintained their prognostic value (P = 0.0005 and 0.0100). These results indicate that outcomes for AML patients appear to be distinguished on the basis of the WHO classification, but the prognostic significance of multilineage dysplasia and prior therapy is lost after adjusting for cytogenetic risk and age. Our findings suggest that the WHO classification may be strengthened by greater emphasis on genetic/cytogenetic information.

Characteristics of acute myeloid leukemia with myelodysplasia‐related changes: A retrospective analysis in a cohort of Chinese patients

“…In the present study with multivariate analysis, we found that MLD is not an independent prognostic factor in patients with AML. Similar to our results, the studies from Wandt et al [16], Haferlach et al [17], Falini et al [18], Miesner et al [19], and Yanada et al [20] all failed to show an independent prognostic effect about OS and DFS for dysplasia in AML. Miesner et al [19] even suggested to restrict the AML-MRC category to cases with a history of MDS or MDS/MPN or myelodysplasia-related cytogenetics completely irrespective of MLD findings, whereas cases solely being defined by morphologic criteria (MLD) should be combined with the AML-NOS category.…”

The 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia: rationale and important changes

“…Dysplasia in at least 50% of the cells in 2 or more hematopoietic lineages was used as a surrogate marker for these MDS-related biologic features. Although the prognostic significance of AML with multilineage dysplasia has been verified in some studies, [89][90][91] …”

Clinical characterization of acute myeloid leukemia with myelodysplasia-related changes as defined by the 2008 WHO classification system

“…The percentage of patients encompassed by the AML-MRC category was 48%, compared with prior reports of AML with multilineage dysplasia comprising 24% to 38%. [6][7][8]18 Overall, 26 patients had an NPM1 mutation (16 were FLT3 mutated), 25 had FLT3-ITD alone, 8 had FLT3-D835 alone, and 9 had a CEBPA mutation (3 were FLT3 mutated). The frequency of these mutations is within the range of prior studies.…”

“…As it relates to AML, this includes limited cytogenetic findings, presence of morphologic dysplasia, and prior therapy. 5 Although later studies have validated this system, [6][7][8] including the importance of multilineage dysplasia, others have suggested that multilineage dysplasia correlates with unfavorable cytogenetics and has no independent impact on prognosis. 9,10 In 2008, a revision of the WHO classification has incorporated recently acquired genetic information into an updated classification scheme of AML.…”