Precision oncology in EGFR positive non-small cell lung cancer: breaking the 10-year barrier—a case report

: Non-small cell lung cancer (NSCLC) is responsible of 85% of lung cancer (LC) cases. Therefore, epithelial growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) were developed and have improved clinical outcomes of EGFR -mutant NSCLC patients. However, these patients inevitably develop resistance to those medications. Some of the resistance mechanisms are T790M mutation and transformation of lung adenocarcinoma to small cell lung cancer (SCLC). Conversely, only a few EGFR -mutant NSCLC cases reported a long-term survival of more than 5 years. The present case concerns a 53-year-old never smoker woman of Hispanic origin, that debuted with dry cough without dyspnea and intermittent high-intensity pain in the left chest and spine. She was diagnosed with metastatic NSCLC and started treatment with platinum-based chemotherapy double. After an EGFR -mutation was identified, the patient started target therapy. Over the years, treatment was escalated because of the resistance she developed against TKIs. T790M resistance mutation was reported and persisted over time; additionally the appearance of TP53 R213 mutation was found years later. Treatment with osimertinib was successfully administered for 10 months and after that meningeal progression was found. At the same time, transdifferentiation to SCLC was confirmed by histological analysis. Carboplatin/etoposide/osimertinib was then unsuccessfully administered. The patient died in January 2020, after 12.5 years of overall survival (OS) and 10 lines of treatment. To our knowledge, this article presents one of the longest reported survivals of a metastatic LC patient with EGFR mutation. 12