Effective treatment with icotinib in advanced lung adenocarcinoma harboring rare EGFR mutation G719A/L833V: A case report

RATIONALE: Mutations in epidermal growth factor receptor (EGFR) play critical roles in the pathogenesis of non–small cell lung cancer (NSCLC), and they are highly associated with sensitivity to tyrosine kinase inhibitors. Targeted therapies are approved for patients with “classical” mutations and a small number of other mutations. However, patients with rare, even double EGFR mutations have different responses to EGFR tyrosine kinase inhibitor, which brings uncertainty to clinical practice. PATIENT CONCERNS: A 74-year-old woman, never-smoker, was presented with chest pain. Chest computed tomography scan showed a big lesion in the right upper lobe with mediastinal lymph nodes metastases. Fine-needle biopsy and pathology suggested lung adenocarcinoma. A rare G719A/L833V double mutation of EGFR was detected in both tissue and plasma samples by next-generation sequencing. Interventions and outcomes: Icotinib was used as first-line therapy and showed good efficacy. Partial response was achieved, and the progression-free survival was 8 months. LESSONS: This is the first report of the icotinib treatment achieving long-lasting and stable disease control in an NSCLC patient with EGFR G719A/L833V mutation. Icotinib could be a first-line treatment option in NSCLC patients harboring EGFR G719A/L833V mutation.