Extraordinary and prolonged erlotinib-induced clinical response in a patient with EGFR wild-type squamous lung cancer in third-line therapy: A case report

Several small molecules, epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs), such as gefitinib, erlotinib and afatinib, have been demonstrated to significantly improve clinical outcomes in patients with advanced EGFR-mutated non-small cell lung cancer (NSCLC), but erlotinib activity in EGFR wild-type squamous carcinoma is still highly debated. Here, we describe a prolonged and unexpected clinical response to erlotinib in a male former heavy cigarette smoker with wild-type EGFR squamous-cell cancer.