Clinical Applications of Chromosomal Microarray Testing in Myeloid Malignancies

Purpose of Review: Knowledge of both somatic mutations and copy number aberrations are important for the understanding of cancer pathogenesis and management of myeloid neoplasms. The currently available standard of care technologies for copy number assessment such as conventional karyotype and FISH are either limited by low resolution or restriction to targeted assessment. Recent Findings: Chromosomal microarray (CMA) is effective in characterization of chromosomal and gene aberrations of diagnostic, prognostic, and therapeutic significance at a higher resolution than conventional karyotyping. These results are complementary to NGS mutation studies. Copy-neutral loss of heterozygosity (CN-LOH), which is prognostic in AML, is currently only identified by CMA. Yet, despite the widespread availability, CMA testing is not routinely performed in diagnostic laboratories due to lack of knowledge on best-testing practices for clinical work-up of myeloid neoplasms. In this review, we provide an overview of the clinical significance of CMA in acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), and myelodysplastic/myeloproliferative neoplasms (MDS/MPN). We will also elaborate the specific clinical scenarios where CMA can provide additional information essential for management and could potentially alter treatment. Summary: Chromosomal microarray (CMA) is an effective technology for characterizing chromosomal copy number changes and copy-neutral loss of heterozygosity of diagnostic, prognostic, and therapeutic significance at a high resolution in myeloid malignancies.