ABSTRACT
Cancer development and progression represent a continuum of biological behavior driven by altered patterns of gene expression. Characterizing the critical gene targets associated with tumor subtypes or different points along the continuum has become the goal of molecular taxonomy of tumors. Molecular classification includes identification of stages or risk factors in the carcinogenic process, genetic signatures that confer the malignant phenotype to provide a biomarker for early detection or diagnosis, prediction of prognosis and response to specific therapies, and identification of fundamental mechanisms that can be targeted for prevention or treatment. Until recently, these studies were done using a candidate gene approach, wherein genes of interest were investigated one at a time. However, cancer phenotypes involve multiple genetic alterations, and not every case with the same phenotype will exhibit the same set of perturbed genes. Consequently, classification of the determinants of biological behavior may require the ability to evaluate patterns of synchronized genetic events.
