Molecular Cytogenetics in Solid Tumors: Laboratorial Tool for Diagnosis, Prognosis, and Therapy

Learning Objectives After completing this course, the reader will be able to: Explain the basic principles supporting the FISH technology and list examples of methodology variants suitable for analysis in metaphase and interphase cells. Describe at least one advantageous and one limiting factor for the expansion of the applicability of FISH assays to solid tumors. Explain technical strategies for detection of chromosomal translocation in nondividing cells. Illustrate applications of cytogenetic markers to solid malignancies for diagnosis, prognosis, selection of therapy, and monitoring disease recurrence or response to treatment. Access and take the CME test online and receive one hour of AMA PRA category 1 credit at CME.TheOncologist.com The remarkable progress in the understanding of leukemogenesis was soundly sustained by methodological developments in the cytogenetic field. Nonrandom chromosomal abnormalities frequently associated with specific types of hematological disease play a major role in their diagnosis and have been demonstrated as independent prognostic indicators. Molecular pathways altered by chimeric or deregulated proteins as a consequence of chromosomal abnormalities have also significantly contributed to the development of targeted therapies, and cytogenetic assays are valuable for selecting patients for treatment and monitoring outcome. In solid tumors, significantly high levels of chromosome abnormalities have been detected, but distinction between critical and irrelevant events has been a major challenge. Consequently, the application of cytogenetic technology as diagnostic, prognostic, or therapeutic tools for these malignancies remains largely underappreciated. The emergence of molecular-based techniques such as fluorescence in situ hybridization was particularly useful for solid malignancies, and the spectrum of their application is rapidly expanding to improve efficiency and sensitivity in cancer prevention, diagnosis, prognosis, and therapy selection, alone or in combination with other diagnostic methods. This overview illustrates current uses and outlines potential applications for molecular cytogenetics in clinical oncology.