Review
Copyright ©2010 Baishideng. All rights reserved.
World J Gastroenterol. Mar 14, 2010; 16(10): 1177-1187
Published online Mar 14, 2010. doi: 10.3748/wjg.v16.i10.1177
Mechanisms of resistance to anti-EGFR monoclonal antibody treatment in metastatic colorectal cancer
Zacharenia Saridaki, Vassilis Georgoulias, John Souglakos
Zacharenia Saridaki, Vassilis Georgoulias, John Souglakos, Department of Medical Oncology, University Hospital of Heraklion and Laboratory of Tumor Cell Biology, Medical School, University of Crete, Heraklion, Crete 71110, Greece
Author contributions: Saridaki Z drafted the article; Georgoulias V and Souglakos J revised it critically for important intellectual content and approved the final version.
Correspondence to: John Souglakos, MD, PhD, Lecturer of Medical Oncology, University Hospital of Heraklion, Voutes and Stavrakia, PO Box 1352, Heraklion, Crete 71110, Greece. georgsec@med.uoc.gr
Telephone: +30-2810-392783 Fax: +30-2810-392857
Received: December 23, 2009
Revised: January 15, 2010
Accepted: January 22, 2010
Published online: March 14, 2010
Abstract

Metastatic colorectal cancer (mCRC) continues to be counted as a major health problem. The introduction of newer cytotoxics, irinotecan and oxaliplatin, has achieved a significant improvement in survival rates. Novel targeted therapies (bevacizumab, and cetuximab) in combination with most efficient chemotherapy regimens have pushed the median survival beyond the 2-year mark and increased the proportion of patients which could benefit from resection of metastatic lesions. In addition, several studies have proved that the CRC mutation profiles should influence patient selection or stratification in prospective trials. KRAS mutational status represents a paradigm for biomarker development in the era of molecular targeted therapies. The present article is an overview of the most important studies in the development of biomarkers for the optimization of anti-epidermal growth factor receptor (anti-EGFR) treatment in mCRC, beyond KRAS mutations, which is a work in progress. The aim will be to identify molecular markers that might be used to select patients with a higher probability of response to anti-EGFR monoclonal antibodies. Overall the accumulating evidence of the molecular biology of CRC has substantially changed the approach to mCRC treatment and has given clinicians more rational options for treating this illness.

Keywords: Colorectal cancer; Epidermal growth factor receptor protein; Monoclonal antibodies; KRAS; BRAF; PIK3CA; Mutation