Lung adenocarcinoma organoids harboring EGFR 19Del and L643V double mutations respond to osimertinib and gefitinib

INTRODUCTION: It has been well reported that non-small-cell lung cancer (NSCLC) patients with single epithelial growth factor receptor (EGFR) activating mutation have high objective response rate when treated with EGFR-TKIs. However, due to rarity of cases, the response of patients with EGFR double or multiple mutations is not yet well understood. Patient-derived organoid technology has become to a powerful tool in cancer personalized medicine. PATIENT CONCERNS: A 60-year-old nonsmoking female was admitted to hospital for lung cancer after Chest CT. DIAGNOSES: The patient had no obvious clinical symptoms. Postoperative pathology confirmed a stage I of NSCLC. An EGFR double mutation 19Del/L643V was detected in the sequence of patient's cancer specimen. INTERVENTIONS: The patient was in good condition after surgical resection, with no sign of lung cancer recurrence. The patient has not yet started on targeted medicine. OUTCOMES: A lung cancer organoid culture was established from the cancer tissue of the patient, which recapitulated the morphological and molecular characteristics of cancer tissue. The drug sensitivity test showed that the cancer organoids that retained original mutations were sensitive to anticancer agents osimertinib and gefitinib, while resistant to erlotinib and icotinib. CONCLUSION: The uncommon EGFR double mutation exhibits distinctive sensitivities towards different target drugs of EGFR-TKIs. Our findings provide a better understanding of EGFR-TKIs' effects on patient-derived cancer organoids harboring uncommon EGFR double mutation(s).