Chapter 5 - In Situ Hybridization

Abstract

In situ hybridization is a flexible, fast, and powerful technique that can detect almost any chromosomal aberration. The slide-based fluorescence in situ hybridization (FISH) or chromogenic in situ hybridization also allows for the characterization of relevant cell types and tissue microenvironment to reveal important information related to tumor heterogeneity or other morphological characteristics. Currently, in situ hybridization gives information on HER2 expression in breast or gastric cancer to predict responses to antibody-based therapies such as trastuzumab, pertuzumab, and ado-trastuzumab emtansine, and in nonsmall cell lung cancer, FISH provides information on anaplastic lymphoma kinase rearrangements used to predict response to treatment with crizotinib. In situ hybridization can be considered a robust technique in the hand of the user when applying validated methods with optimal specificity, sensitivity, and method design. The benefits of slide-based diagnosis allow pathologists to rapidly identify and characterize drug-relevant aberrations of advanced disease, and in situ hybridization will continue to be an important test method used to predict effective drug responses.