Outcome of EGFR inhibitors treatment in advanced NSCLC patients, not enrolled in clinical trials

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have become a treatment after first-line chemotherapy in patients with advanced NSCLC. We assessed the predictive and prognostic role of EGFR and Kras mutations in NSCLC patients treated with TKIs after progression, not included in clinical trials. Gefitinib 250 mg or Erlotinib 150 mg per os were administered to 70 patients. Radiological assessment was performed every six weeks. EGFR and Kras mutations were found in 21.4% and 24.3% of patients, respectively. At multivariate analysis, Kras mutation was positively associated with progression-free survival (PFS; HR=0.71, 95% CI: 0.53-0.96; p=0.027) and, less clearly, with response (OR=1.84, 95% CI: 0.98-3.45; p=0.057) and survival (HR=0.74, 95% CI:0.54-1.02; p=0.066). EGFR mutation influenced positively PFS (HR=0.69, 95% CI: 0.47-1.02; p=0.06), but not survival. In conclusion, in our unselected patients mutation of Kras correlated with a better outcome. The small number of patients may explain some discrepancies with data in literature.