title: Current companion diagnostics in advanced colorectal cancer; getting a bigger and better piece of the pie.
abstract: While the treatment of colorectal cancer continues to rely heavily on conventional cytotoxic therapy, an increasing number of targeted agents are under development. Many of these treatments require companion diagnostic tests in order to define an appropriate population that will derive benefit. In addition, a growing number of biomarkers provide prognostic information about a patient's malignancy. As we learn more about these biomarkers and their assays, selecting the appropriate companion diagnostic becomes increasingly important. In the case of many biomarkers, there are numerous assays which could provide the same information to a treating physician, however each assay has strengths and weaknesses. Institutions must balance cost, assay sensitivity, turn-around time, and labor resources when selecting which assay to offer. In this review we will discuss the current state of companion diagnostics available in metastatic colorectal cancer and explore emerging biomarkers and their assays. We will focus onKRAS, BRAF, HER2,andPIK3CAtesting, as well as microsatellite stability assessment and multigene panels.
authors.affiliation: Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Loree
authors.affiliation: Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Kopetz
authors.affiliation: Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Kanwal P S
authors.initials: KP
authors.lastname: Raghav
keywords: Colorectal cancer; biomarker; companion diagnostic; next generation sequencing (NGS)