Implications of Rapid IDH1/IDH2 Testing for Liquid and Solid Tumors

This seminar reviews clinical utility of adopting rapid IDH1/2 testing in both hematological and solid tumors and describes the adjusted workflow developed. Isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) are enzymes involved in cellular metabolism and cellular differentiation. Mutations in the IDH1 and IDH2 genes alter their enzymatic activity to produce an oncometabolite. Disease-associated variants in IDH1/2 have clinical implications for multiple forms of cancer. Molecular detection of IDH1 and IDH2 disease-associated variants aids in diagnosis, prognostic stratification, and treatment decisions. For example, detection of IDH variants in acute myeloid leukemia (AML) allows for the addition of IDH-targeted therapies to treatment regimens. Additionally, the diagnosis and prognosis of gliomas are dependent on the IDH1/2 molecular status. In these ways, it is increasingly important to have rapid molecular testing for IDH1/2. Challenges of implementing IDH testing include redundant testing (immunohistochemistry and massively parallel sequencing) and limited specimen material. In order to address these challenges, the clinical utility of rapid IDH1/2 testing was evaluated and modifications to the laboratory workflow were explored. These studies highlight the value of rapid IDH testing and show that procedural adjustments can both streamline laboratory workflows and conserve vital limited specimen material.