Clinical features and prognostic impact of PRDM16 expression in adult acute myeloid leukemia

High PRDM16 (also known as MEL1) expression is a representative marker of acute myeloid leukemia (AML) with NUP98-NSD1 and is a significant predictive marker for poor prognosis in pediatric AML. However, the clinical features of adult AML with PRDM16 expression remain unclear. PRDM16 is highly homologous to MDS1/EVI1, which is an alternatively spliced transcript of MECOM (also known as EVI1). We investigated PRDM16 expression in 151 AML patients, with 47 (31%) exhibiting high PRDM16 expression (PRDM16/ABL1 ratio >= 0.010). High PRDM16 expression significantly correlated with DNMT3A (43% vs. 15%, P<0.001) and NPM1 (43% vs. 21%, P=0.010) mutations and partial tandem duplication of KMT2A (22% vs. 1%, P<0.001). Remarkably, high-PRDM16-expression patients were frequent in the noncomplete remission group (48% vs. 21%, P=0.002). Overall survival (OS) was significantly worse in high-PRDM16-expression patients than in low-PRDM16-expression patients (5-year OS, 18% vs. 34%; P=0.002). This trend was observed more clearly among patients aged <65 years (5-year OS, 21% vs. 50%; P=0.001), particularly in FLT3-ITD-negative patients in the intermediate cytogenetic risk group (5-year OS, 25% vs. 59%; P=0.009). These results suggest that high PRDM16 expression is a significant predictive marker for poor prognosis in adult AML patients, similar to pediatric AML patients.