Predictive tissue biomarkers for bevacizumab-containing therapy in metastatic colorectal cancer: an update

• Published in: Expert review of molecular diagnostics Vol. 15; no. 3; p. 399
• Main Authors: Marien, Koen M, Croons, Valerie, Martinet, Wim, De Loof, Hans, Ung, Christopher, Waelput, Wim, Scherer, Stefan J, Kockx, Mark M, De Meyer, Guido R Y
• Format: Journal Article
• Language: English
• Published: England 01.03.2015
• Subjects: Angiogenesis Inhibitors - administration & dosage; Animals; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Bevacizumab - administration & dosage; Biomarkers, Tumor - genetics; Biomarkers, Tumor - metabolism; Colorectal Neoplasms - diagnosis; Colorectal Neoplasms - drug therapy; Colorectal Neoplasms - genetics; Colorectal Neoplasms - metabolism; Humans; Immunohistochemistry; Mice; Neoplasm Metastasis; Neovascularization, Pathologic - genetics; Neovascularization, Pathologic - metabolism; Prognosis; Signal Transduction - drug effects; Tumor Microenvironment - genetics; Vascular Endothelial Growth Factor A - metabolism; VEGF inhibitor; anti-angiogenesis; bevacizumab; metastatic colorectal cancer; immunohistochemistry; predictive biomarker; Avastin
• ISSN: 1744-8352
• DOI: 10.1586/14737159.2015.993972

Bevacizumab is the first anti-angiogenic agent approved for the treatment of metastatic colorectal cancer. The need for patient selection before initiating therapy necessitates the study of various proteins expressed in metastatic colorectal cancer tissue as candidate predictive markers. Immunohistochemistry is a valuable, commonly available and cost-effective method to assess predictive biomarkers. However, it is subject to variations and therefore requires rigorous protocol standardizations. Furthermore, validated quantification methodologies to study these angiogenic elements have to be applied. Based on their function in tumor angiogenesis and their relation to the mechanism of action of bevacizumab, protein markers were divided in four groups: VEGF A-signaling proteins; other relevant angiogenesis factors; factors regarding the tumor microenvironment and tumor intrinsic markers. Conceivably, nimbly selecting a small but relevant group of therapy-guided patients by the appropriate combination of predictive biomarkers may confer great value to this angiogenic inhibitor.