Lung adenocarcinoma harboring rare epidermal growth factor receptor L858R and V834L mutations treated with icotinib: A case report

BACKGROUND: Epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitors are widely used for the treatment of non-small-cell lung cancer with EGFR mutations. However, patients with rare, even compound EGFR mutations have different responses to EGFR-tyrosine-kinase inhibitors, which bring uncertainty to clinical treatment. CASE SUMMARY: A 45-year-old female patient presented with a 3-mo history of cough and white sputum without chest pain. Chest computed tomography revealed lung space-occupying lesions and multiple lymphadenectasis. Bronchoscopy and pathology suggested lung adenocarcinoma. Compound variation of EGFR gene (exon 21 L858R/V834L) was detected in both tissue and circulating tumor deoxyribonucleic acid samples. As a result of next-generation sequencing and her family’s wishes, the patient was given oral treatment with icotinib hydrochloride (125 mg/d, tid) from March 21, 2019 and has achieved stable disease for the last 1 year. CONCLUSION: Non-small cell lung adenocarcinoma with EGFR L858R/V834L was treated successfully with icotinib, and it may be a new medication treatment option.