EGFR and non-small cell lung carcinoma: In addition, some studies found that in patients with advanced NSCLC who have lost the opportunity for surgery and were treated with gefitinib (an epidermal growth factor tyrosine kinase inhibitor, EGFR-TKI), the progression-free survival (PFS) and OS significantly reduced with increased in plasma NSE level before treatment, indicating that high pre-treatment serum level of NSE predicted poor EGFR-TKI therapeutic effect.