Successful treatment of an elderly patient with an uncommon L861Q epidermal growth factor receptor mutation with low‐dose afatinib: A case report

There are limited data on the clinical efficiency of afatinib in non-small cell lung cancer (NSCLC) patients with uncommon epidermal growth factor receptor (EGFR) mutations. Moreover, the efficacy and safety of afatinib in elderly patients with these mutations has not been established. Here, we describe a case of successful treatment of a patient aged >80 years with lung adenocarcinoma positive for the uncommon EGFR L861Q mutation with low-dose afatinib. An 83-year-old woman presented with cough and dyspnea. A chest computed tomography (CT) scan revealed tumors in the left upper lobe, left pleural effusion, and multiple lung metastases in both lungs. The patient was diagnosed with lung adenocarcinoma with an EGFR L861Q mutation based on cytological findings. The patient received 30 mg/day of afatinib and experienced no severe adverse events. Two weeks later, partial response was observed based on a CT scan. The results of the present case support the effectiveness and safety of low-dose afatinib in elderly patients with EGFR L861Q mutation-positive NSCLC.