The NPM1 mutation type has no impact on survival in cytogenetically normal AML

Abstract

NPM1 mutations represent frequent genetic alterations in patients with acute myeloid leukemia (AML) associated with a favorable prognosis. Different types of NPM1 mutations have been described. The purpose of our study was to evaluate the relevance of different NPM1 mutation types with regard to clinical outcome. Our analyses were based on 349 NPM1-mutated AML patients treated in the AMLCG99 trial. Complete remission rates, overall survival and relapse-free survival were not significantly different between patients with NPM1 type A or rare type mutations. The NPM1 mutation type does not seem to play a role in risk stratification of cytogenetically normal AML.

Trial registration: ClinicalTrials.gov NCT00266136.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1. Overall Survival (OS) and Relapse-Free Survival (RFS) in 349 patients with cytogenetically normal acute myeloid leukemia and NPM1 mutation treated in the AMLCG99 study.

(A) OS in patients with NPM1 type A mutation versus NPM1 rare type mutation. (B) OS in patients with NPM1 type A mutation versus NPM1 rare type mutation with or without an additional FLT3-ITD. (C) RFS in patients with NPM1 type A mutation versus NPM1 rare type mutation. (D) RFS in patients with NPM1 type A mutation versus NPM1 rare type mutation with or without an additional FLT3-ITD. Abbreviations: CR, complete remission; FLT3-ITD+, presence of an internal tandem duplication in the fms-related tyrosine 3 gene; FLT3-ITD-, absence of an internal tandem duplication in the fms-related tyrosine 3 gene; NPM1-A, mutation in the nucleophosmin gene consisting of an insertion of the tetranucleotide TCTG; NPM1-RA, mutation in the nucleophosmin gene other than type A.

Figure 2. Overall Survival (OS) and Relapse-Free Survival (RFS) in 349 patients with cytogenetically normal acute myeloid leukemia and NPM1 mutation treated in the AMLCG99 study.

(A) OS in patients with NPM1 type A mutation versus NPM1 type B mutation versus NPM1 type D mutation versus NPM1 type other mutation. (B) RFS in patients with NPM1 type A mutation versus NPM1 type B mutation versus NPM1 type D mutation versus NPM1 type other mutation. Abbreviations: CR, complete remission; FLT3-ITD+, presence of an internal tandem duplication in the fms-related tyrosine 3 gene; FLT3-ITD-, absence of an internal tandem duplication in the fms-related tyrosine 3 gene; NPM1-A, mutation in the nucleophosmin gene consisting of an insertion of the tetranucleotide TCTG; NPM1-B, mutation in the nucleophosmin gene consisting of an insertion of the tetranucleotide CATG, NPM1-D, mutation in the nucleophosmin gene consisting of an insertion of the tetranucleotide CCTG, NPM1-other, mutation in the nucleophosmin gene other than NPM1 mutation types A, B, D.