Abstract
Epidermal growth factor receptor (EGFR) plays an important role in the development and progression of human epithelial carcinomas including the non-small-cell lung carcinoma (NSCLC). Activation of the EGFR signalling pathway promotes tumour growth and progression, stimulates tumour cell proliferation and production of angiogenic factors, tumour invasion and metastasis formation, and suppresses apoptosis.
Numerous studies have confirmed the predictive role of activation mutations, especially in exons 19 and 21 of EGFR gene in NSCLC. The mutations are unambiguously associated with enhanced efficacy of tyrosine kinase inhibitors (TKIs) of EGFR.
Medications at our disposal include reversible first-generation EGFR TKIs erlotinib and gefitinib, irreversible second-generation EGFR TKI afatinib and also the irreversible third-generation EGFR TKI osimertinib - the latter is indicated mainly for the resistant mutation T790M.