Genomic Subclassification and Risk Stratification of ALL.

BACKGROUND: Over the last 2 decades, significant improvements have been made in the understanding of the genomic and biological bases of acute lymphoblastic leukemia (ALL), resulting in enhanced genomic classification, more precise risk stratification, and improved long-term outcomes. ALL is a hematologic malignancy defined by uncontrolled proliferation of immature B- or T-lymphoid blasts in the bone marrow, blood, and other extramedullary tissues. It affects most commonly children, representing the most common childhood cancer, but it also occurs in adults where outcome tends to be poorer compared to pediatric patients.

SUMMARY: A variety of genetic aberrations, including structural and numerical chromosome alterations, translocations generating fusion oncoproteins, cryptic genomic rearrangements, sequence mutations, and genomic copy number changes, define multiple genomic subtypes, influence risk stratification and determine response to therapeutic strategies.

KEY MESSAGES: In this review, we describe the updated genomic classification of ALL highlighting new biological insights and discussing their implications for prognostication and outcome.