The clinical relevance of BAALC and ERG expression levels in pediatric AML

Abstract

Pediatric acute myeloid leukemia (AML) is a heterogeneous disease,1 for which survival rates have increased up to 70% over the past years.2 Approximately 45% of adult AML patients and 20% of pediatric AML patients are diagnosed with cytogenetically normal AML (CN-AML), which is currently classified and treated as a homogeneous intermediate-risk group.3 For future stratification of pediatric CN-AML, it is important to unravel the underlying molecular aberrations. For example, single-gene mutations such as NPM1 and CEBPA double mutations appeared to predict favorable outcome, whereas WT1 mutations and the cryptic NUP98/NSD1 translocation4 are of poor prognostic significance. In adult AML patients, the expression levels of specific genes have been associated with prognosis, mainly in CN-AML. For instance, high expression levels of BAALC (brain and acute leukemia cytoplasmic; 8q22) or ERG (E26 transformation-specific-related; 21q22) genes predict a poor prognosis in most adult AML studies, confined to CN-AML, as described by Schwind et al.5