A Case of Lung Adenocarcinoma With Concurrent EGFR Mutation and ALK Fusion Combined With Literature Review.

This case underscores the critical importance of retesting for resistant mechanisms, such as EML4-ALK fusion, in patients with EGFR-mutant lung adenocarcinoma who experience rapid progression on EGFR-tyrosine kinase inhibitor (TKI) therapy. Early identification of such co-alterations and an immediate switch to alectinib can lead to rapid and sustained clinical improvement.