The evolving scenario of EGFR+ NSCLC patients. Old bedrocks and new horizons

Mutations of the Epidermal Growth Factor Receptor (EGFR) in Non Small Cell Lung Cancer (NSCLC) patients represent one of the best examples of oncogene-addiction in solid tumor. Discovered almost 20 years ago, these alterations are detectable in ≈20% of Caucasian patients with non-squamous lung carcinoma, increasing until 60% in the Asian population. ldentification of EGFR aberrations is, nowadays, a cornerstone of NSCLC patients' journey. Treating them with specific small inhibitors (tyrosine kinase inhibitors, TKls) has been demonstrating paradigmatic improvements in terms of quantity and quality of life, both at early and advanced disease stage. Preclinical and clinica! researchers are working to further refine diagnostic algorithms and treatment scenarios. More recent sequencing platforms gave insights on rare EGFR mutations, that should be properly targeted, and mechanisms of resistance emerging along treatments. Undoubtedly, EGFR+ patients will witness other forthcoming milestones in their clinica! management, such as more effective combinatoria! strategies, TKI administration to locally-advanced patients and new molecules for "orphan" uncommon alterations. These and other relevant aspects are discussed in this book with a focus on "state of the art" algorithms and key open questions, both from a biologica! and clinica! perspective.