Nucleophosmin gene-based monitoring in de novo cytogenetically normal acute myeloid leukemia with nucleophosmin gene mutations: comparison with cytofluorimetric analysis and study of Wilms tumor gene 1 expression

Abstract

We compared the clinical value of minimal residual disease (MRD) monitoring by cytofluorimetric methods, Wilms tumor gene 1 (WT1) expression and the study of nucleophosmin gene (NPM) mutations in a series of 26 patients with NPM-mutated de novo acute myeloid leukemia (NPM-AML) who achieved complete hematological remission after conventional chemotherapy. The relapse risk was significantly lower only in patients achieving a NPM molecular complete response (NPM mol-CR) and confirmed NPM mol-CR (non-detectable NPM mutations in two consecutive marrow samples). The disease-free survival (DFS) of patients achieving a < 4-log or ≥ 4-log reduction in NPM value after induction therapy was 12.6 % and 50%, respectively, at 36 months (p = 0.009). The attainment of a confirmed NPM-CR had a significant influence on overall survival (OS at 36 months was 64.3% and 11.9% in patients obtaining or not obtaining confirmed NPM-CR, respectively, p < 0.03). We confirm that NPM-molecular relapse (NPM-rel) is always followed by hematological relapse (H-rel), but longitudinal studies of NPM mutations may predict an impending H-rel earlier than flow cytometric- or WT1-based methods.

Keywords::

• NPM
• MRD
• WT1
• AML

Acknowledgement

This work was partially supported by Ministero dell’Istruzione, dell’Università e della Ricerca (PRIN n° 2007WEYB3A).

Potential conflict of interest

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