Predictors of clinical responses to hypomethylating agents in acute myeloid leukemia or myelodysplastic syndromes

Azacitidine and decitabine, two hypomethylating agents, are known to be effective in the treatment of high-risk myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) patients who cannot endure intensive cytotoxic chemotherapy or are not eligible for transplantation. However, the treatment response rate is low. The molecular mechanisms underlying the resistance to demethylation therapy are unclear. Though a wide range of predictors of treatment response have been investigated, no consensus has been reached. It is imperative to identify certain parameters that can help distinguish between patients who will obtain a favorable outcome from demethylation therapy and those who will not. Here, we describe currently researched potential predictors based on clinical characteristics, DNA methylation, gene mutation, gene expression, microRNAs, and protein expression. Although these parameters are not currently used in clinical practice, this review provides new sights into available clinical and experimental research. Moreover, this paper provides useful information on AML/MDS management.