Molecular Heterogeneity and Receptor Coamplification Drive Resistance to Targeted Therapy in MET -Amplified Esophagogastric Cancer

Coamplification of driver oncogenes occurs frequently in EGC and can drive therapeutic resistance, supporting a role for comprehensive molecular analysis prior to targeted therapy. EGCs can also exhibit extensive heterogeneity in gene amplification between distinct tumor lesions within the same patient, suggesting that molecular profiling of a single-lesion biopsy may be insufficient to guide targeted therapy selection.