Concomitant EGFR mutation and ALK rearrangement in lung adenocarcinoma is more frequent than expected: Report of a case and review of the literature with demonstration of genes alteration into the same tumor cells

Abstract

Oncogenic drivers in lung non-small-cell lung cancer (NSCLC) are considered mutually exclusive, but a review of the literature reveals that concomitant EGFR mutations and ALK rearrangement may occur in a subset of NSCLC. We report here a case of pulmonary adenocarcinoma with concomitant EGFR mutation in exon 21 (L858R) and ALK rearrangement in naive and relapsed tumors. Tumor cells seem to harbor both gene alterations and the patient had a long-lasting response both to EGFR inhibitor in second line and ALK inhibitor once tumor progressed. A speculative discussion on molecular mechanisms underlying this uncommon phenomenon and practical points about epidemiologic, clinicopathologic features and therapeutic options in this intriguing subset of double-positive tumor are reported.