A Real-World, Observational, Prospective Study to Assess the Molecular Epidemiology of Epidermal Growth Factor Receptor (EGFR) Mutations upon Progression on or after First-Line Therapy with a First- or Second-Generation EGFR Tyrosine Kinase Inhibitor in EGFR Mutation-Positive Locally Advanced or Metastatic Non-Small Cell Lung Cancer: The ‘LUNGFUL’ Study

Background: Real-world data on the molecular epidemiology of EGFR resistance mutations at or after progression with first- second-generation EGFR-TKIs in patients advanced NSCLC are lacking. Methods: This ongoing observational study was carried out by 23 hospital-based physicians Greece. The decision to perform cobas®EGFR Mutation Test v2 tissue and/or plasma disease made before enrollment. For negative/inconclusive T790M plasma-based results, re-biopsy could be performed. Results: Ninety-six (96) eligible were consecutively enrolled (median age: 67.8 years) between July-2017 and September-2019. Of patients, 98% tested upon using 2% tissue/cytology biopsy. mutation detected 16.0% liquid biopsies. Tissue performed 22.8% a T790M-negative result. In total, positivity rate 21.9%, not differing EGFR-TKI. Higher (≥2) ECOG performance status longer (≥10 months) time following EGFR-TKI treatment initiation associated positivity. Conclusions: Results from plasma/tissue-cytology samples real-world setting, yielded lower than previous reports. Fewer one four negative testing underwent re-biopsy, indicating challenges routine care settings.