Microarray analysis in the clinical management of cancer

A cancer cell is characterized by alterations in expression of hundreds if not thousands of genes. Given the complexity of these changes, it is not surprising that significant heterogeneity exists in terms of prognosis and treatment response, both among different tumor types and within a given tumor class. A method capable of assaying these changes would undoubtedly contribute significantly to our understanding and management of this disease. In the late 1980s the authors' laboratory was the first to develop and use a methodology that enabled global patterns of gene expression to be assayed in a single sample. This approach, now developed as microarray analysis, has generated enormous interest and is becoming routinely used for multiple purposes, including gene discovery, tumor classification, and prediction of tumor prognosis and response to therapy. This article discusses the basis of this technology and highlights studies that have demonstrated its potential to enhance our understanding and management of cancer.