As a first-generation epidermal growth factor receptor-tyrosine kinase inhibitor, gefitinib was approved by the US Food and Drug Administration for treatment of advanced non-small cell carcinoma with sensitizing EGFR mutations.
Multivariate analysis showed that EGFR mutations were more prevalent in never-smokers (83.3% versus 16.7%, p = 0.006) and patients diagnosed as NSCC favor SqCC (46.2% versus 5.2%, p = 0.001).
The presence of the Q787Q EGFR polymorphism significantly and negatively affected the overall survival rate among patients with non-small-cell carcinoma (p = 0.011), particularly those with squamous cell carcinoma (p = 0.037).
Liver rebiopsy identified an afatinib-resistant combined SCLC and non-small cell carcinoma with neuroendocrine morphology, retaining the EGFR exon 19 deletion.