Chemotherapy combined with Endostar as salvage treatment for EGFR-tyrosine kinase inhibitor primary resistance in an advanced non-small cell lung cancer patient with EGFR L858R mutation and ROS1 fusion: A case report

Abstract

EGFR-activating mutations have been recognized as the most important predictor of response to EGFR-tyrosine kinase inhibitors (TKIs); however, 20-30% of patients harboring EGFR-activating mutations show poor responses. The mechanisms of such EGFR-TKI primary resistance are still poorly understood. In our case, a non-small cell lung cancer patient developed intrinsic EGFR-TKI resistance and was then confirmed to simultaneously harbor an L858R mutation and ROS1 rearrangement. Salvage chemotherapy plus Endostar showed enduring therapeutic effects, achieving a disease-free survival period of 24 months and overall survival of 30 months. This suggests that co-activation of different oncogenic signal pathways might be a potential mechanism of EGFR-TKI primary resistance. Chemotherapy combined with anti-angiogenesis should be considered an important salvage strategy. Further studies are warranted to verify these findings and explore the underlying mechanisms involved.

Keywords: EGFR; ROS1; Chemotherapy; non-small cell lung cancer; primary resistance.