Background: Epidermal growth factor receptor (EGFR) in trans-C797S alteration has been considered as one of the mechanisms, which leads to the resistance to third-generation tyrosine kinase inhibitors (TKI). Several reports have suggested that combination therapy with first- and third-generation TKIs might be effective for acquired trans-C797S alteration.
Case Presentation: Herein, we report a patient diagnosed with lung adenocarcinoma harboring EGFR 19Del/T790M/in trans-C797S mutations with co-occurring CTNNB1 alteration showing a negative response to combination therapy with first- and third-generation TKIs.
Conclusion: Our report highlights the importance of deploying more informed molecular diagnosis and real-time monitoring strategies to detect co-alterations that drive disease progression and drug resistance, in order to find more effective treatment.
Keywords: EGFR, in trans-C797S, CTNNB1, resistance