Long-term complete response to gefitinib after treatment termination in a patient with recurrent post-operative EGFR-mutated lung adenocarcinoma: case report and literature review

Non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations is highly sensitive to EGFR-tyrosine kinase inhibitor (EGFR-TKI). However, few cases of advanced NSCLC completely cured by EGFR-TKIs have been reported. We present an extremely rare case of lung adenocarcinoma that was completely cured by gefitinib administration. A 36-year-old Japanese woman was diagnosed with clinical Stage IIIB (T2N3M0) lung adenocarcinoma originating from the left upper lobe in April 2006. After the two cycles of chemotherapy, it was down-staged to ycStage IA (T1N0M0). She underwent a thoracotomy with left upper lobectomy, pulmonary angioplasty, and mediastinal nodal dissection in July 2006 [ypStage IIIA (T3N1M0)]. Eighteen months later, she was found to have lymphadenopathy of the right supraclavicular nodes. Fine needle aspiration cytology of the lymph node indicated adenocarcinoma. She started gefitinib therapy for recurrent lung cancer with EGFR mutation (exon 19 deletion) in January 2008. Four months afterward, computed tomography (CT) showed her right supraclavicular nodes had shrunk dramatically. Treatment with gefitinib was continued. Thereafter, no disease progression was observed throughout her approximately 8-year gefitinib treatment, and gefitinib was terminated in November 2016. Although the patient received no other treatment, she has suffered no recurrence in the 4 years since. A review of the literature, including our case, is also presented.