Non - small cell lung cancer (NSCLC) is the largest subgroup of lung cancers, responsible for about 80% of all lung cancers. Targeted cancer therapy has opened a new window into treatment of non - small cell lung cancer. This therapy is very effective for patients who have EGFR (Epidermal growth factor receptor) activating mutations, primarily located in the tyrosine kinase domain in the form of a base - pair deletion at exon 19 (LREA deletions, accounting for about 54%) or a point mutation at exon 21 (L858R, accounting for about 43%). EGFR activating mutations occur in about 20% of NSCLC patients. | Targeting TKI resistance in non - small cell lung cancer patients caused by secondary EGFR T790m mutation
