Protein correlates of molecular alterations in lung adenocarcinoma: Immunohistochemistry as a surrogate for molecular analysis

Most clinically actionable alterations in lung adenocarcinomas are detected using molecular or cytogenetic techniques. However, many such alterations have a protein-level correlate that can be interrogated using immunohistochemistry. This review will summarize the therapeutic relevance of predictive biomarkers in lung adenocarcinoma including the oncogenes EGFR, MET, ALK, RET, and ROS1 and tumor suppressors PTEN and LKB1 with an emphasis on established and emerging protein immunohistochemistry reagents and their promise in clinical practice.