Molecular tumor profiling for prediction of response to anticancer therapies.

Personalized medicine in the treatment of cancer is based on the recognition that molecularly targeted therapies are most effective in patients whose tumors carry specific genetic or genomic alterations. These alterations, which often activate oncogenes that encode the components of signal transduction pathways, serve as predictive markers for sensitivity or resistance of individual tumors to drugs that target such pathways. In the recent past, individual mutations and other changes within tumors have been assayed to determine the likelihood of response or nonresponse to specific targeted therapies. However, with the development of increasing numbers of molecularly targeted drugs, attention has shifted to high-throughput testing of tumors for dozens of predictive markers. This approach to predictive testing has been termed molecular tumor profiling. This review describes the background to this field, the principal markers analyzed, and the methodologies that are being utilized or are under development for tumor profiling.