Activating and resistance mutations of the epidermal growth factor receptor (EGFR) gene and non-small cell lung cancer: a clinical reality

Abstract

In non-small cell lung cancer, the EGFR gene mutations identify a patient sub-population with different clinical characteristics and treatment responses to those that do not have these mutations. There are mutations that derive in increased sensitive to EGFR targeted therapy, as well as mutations that result in resistance. The determination of EGFR mutations involves a change in the therapeutic approach to lung cancer patients in current clinical practice. In this article we present a case of a patient suffering from a metastatic lung adenocarcinoma with an activating mutation on diagnosis, initially responding to treatment with erlotinib, who subsequently developed a secondary resistance due to acquiring the T790M mutation in exon 20 of the EGFR gene.