Predictive Markers in Colon Cancer Biomarkers in Oncology

Over the past several decades, significant progress has been achieved towards improving survival outcome of patients with colorectal cancer (CRC), which is attributed in part to the approval and incorporation of several new drugs. Currently, a lack of validated predictive biomarkers for almost all therapeutic agents restricts our ability to tailor specific drugs to patient cohorts, and might be viewed as one of the largest barriers to the success of individualized CRC therapy. In recent years, the majority of efforts have been placed on the identification of predictive biomarkers in CRC, which in turn would allow for selecting patients who will benefit from a particular therapeutic regimen. Despite a plethora of promising predictive biomarkers evaluated, KRAS status remains the only marker with sufficient evidence to justify routine clinical assessment for selection of anti-EGFR therapy in metastatic CRC (mCRC) patients. Although there is no doubt that implementation KRAS testing represents a significant step forward in the concept of individualized treatment in mCRC, it is becoming increasingly apparent that disease progression is largely driven by a multitude of signaling pathways, resulting in the critical need to implement a pathway-based approach whereby analysis of multiple steps within the molecular cascades being targeted is considered and evaluated.