Concurrent Small-Cell Transformation and Emergence of Trans-C797S and T790M Mutations Under Sequential Treatment With EGFR Inhibitors in Lung Adenocarcinoma.

Epidermal growth factor receptor ( I EGFR i ) gene mutations are strong oncogenic drivers in a subset of non-small-cell lung cancer (NSCLC). Synopsis of therapeutic history and histologic and molecular analysis of the present patient showing tumor evolution toward small-cell lung cancer (SCLC) transformation and accumulation of epidermal growth factor receptor (EGFR) genetic abnormalities. Because neuroendocrine cancer cells retained I EGFR i -activating mutation, the increase in allelic frequency of I EGFR i del19 could be explained in our patient by the SCLC transformation. 15 Yu HA, Arcila ME, Rekhtman N, et al: Analysis of tumor specimens at the time of acquired resistance to EGFR-TKI therapy in 155 patients with EGFR-mutant lung cancers. [Extracted from the article]