Surrogate predictive biomarkers for response to anti-EGFR agents: state of the art and challenges.
The epidermal growth factor receptor (EGFR) plays a key role in cancer development and progression in several human malignancies including non-small cell lung cancer (NSCLC). Several strategies aimed at inhibiting the EGFR have been investigated in the last years, including the use of small tyrosine kinase inhibitors (TKIs) directed against the intracellular domain of the receptor and monoclonal antibodies targeting its extracellular portion. Subgroups of patients who are more likely to respond to TKIs have been identified based on both clinical and biological features. Never-smoking history has emerged as the most relevant clinical characteristic predictive of response to TKIs in NSCLC, while presence of drug-sensitive EGFR mutations and EGFR gene gain represent critical biological variables associated with an improved outcome for patients exposed to these agents. Recent studies have highlighted the existence of biological factors involved in intrinsic and acquired resistance to TKIs, including k-ras, HER-2 and EGFR exon 20 mutations. Increasing knowledge of EGFR biology and drug-receptor interactions will allow to identify individuals who are likely to derive a clinical benefit from the proposed targeted therapy, sparing refractory patients expensive and potentially toxic treatment.
Cappuzzo
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F
Department of Oncology-Hematology, Istituto Clinico Humanitas IRCCS, Rozzano, Milan, Italy. federico.cappuzzo@humanitas.it
Toschi
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L
Finocchiaro
G
G
Ligorio
C
C
Santoro
A
A
D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D015415:Biomarkers / Q000032:analysis*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy*; D000068818:Cetuximab; D019008:Drug Resistance, Neoplasm; D066246:ErbB Receptors / Q000187:drug effects* / Q000235:genetics; D000069347:Erlotinib Hydrochloride; D000077156:Gefitinib; D018628:Gene Dosage; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000188:drug therapy*; D010750:Phosphoproteins / Q000032:analysis; D011237:Predictive Value of Tests; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D051057:Proto-Oncogene Proteins c-akt / Q000032:analysis; D011799:Quinazolines / Q000627:therapeutic use; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D020893:Receptor, ErbB-3 / Q000032:analysis
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D015415:Biomarkers; D000068818:Cetuximab; D066246:ErbB Receptors; D000069347:Erlotinib Hydrochloride; D000077156:Gefitinib; D010750:Phosphoproteins; D047428:Protein Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; D011799:Quinazolines; D020794:Receptor Protein-Tyrosine Kinases; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3; C494918:AKT1 protein, human