Adenosquamous cell lung cancer successfully treated with gefitinib: A case report.

Although adenosquamous cell lung cancer (ASCLC) is included in the non-small-cell lung cancers (NSCLCs), the number of currently available studies on the response of this type of cancer to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) is limited. This is the case report of a 66-year-old female who was referred to the Mito Medical Center (Mito, Japan) with hemoptysis and the chest computed tomography (CT) scan revealed a large cavitary mass in the lower lobe of the left lung. The patient underwent surgical resection of the lesion and the final pathological diagnosis was ASCLC staged as pT2bN2M0. Notably, an EGFR exon 19 deletion was identified in the adenocarcinomatous as well as the squamous cell carcinomatous components of the tumor. Despite adjuvant chemotherapy, the patient developed small cavitary metastases in the lungs bilaterally. Therefore, treatment with gefitinib was initiated. The chest CT scan revealed substantial regression of the metastatic cavitary tumors in both lungs, with thinning of the walls. The patient remains alive and recurrence-free 19 months following the initiation of gefitinib therapy. This case demonstrated an optimal clinical response to gefitinib treatment for EGFR mutation-positive ASCLC, suggesting that gefitinib is a therapeutic option for such a subset of patients with ASCLC.