Genetic tools for risk-stratification in multiple myeloma

Genetic studies have a central role in the study of multiple myeloma (MM), as they become a critical component in the risk-based stratification of the disease. Significant efforts have been made to identify genetic changes and signatures that can predict clinical outcome and include them in the routine clinical care. Fluorescence in situ hybridization (FISH) still remains the most used genetic technique in clinical practice, mostly due to its very straightforward implementation and the simplicity of data analysis. The advent of high-resolution genomics (i.e. array CGH, exome and whole genome sequencing) and transcriptomics tests (i.e. gene expression profiling - GEP, and mRNA sequencing) provide a comprehensive analysis of the already defined genetic prognostic factors and are helpful tools for the identification of potential novel disease markers on the MM tumor clone. Indeed, GEP has been successfully implemented in MM as a risk-stratification tool, holding the greatest power in outcome discrimination. Nevertheless, some technical and logistic intricacies (need of a highly purified tumor clone, cost of the assay and complexity of data analysis) need to be considered before the definitive incorporation of high-throughput technologies in routine clinical tests. Until then, FISH remains the standard tool for genomic abnormality detection and disease prognostication.