Association of BIM Deletion Polymorphism and BIM-γ RNA Expression in NSCLC with EGFR Mutation

Aim: This pilot study assessed the association of BIM deletion polymorphism and BIM RNA isoform in patients with EGFR-positive non-small cell lung cancer (NSCLC). Patients and Methods: The study included 33 patients with EGFR-positive NSCLC treated with gefitinib. BIM deletion polymorphism and BIM RNA isoform (EL/L/S/gamma) were determined by polymerase chain reaction (PCR). Results: BIM-gamma expression was significantly higher in patients with BIM deletion polymorphism than among those without BIM deletion polymorphism inside tumors (p=0.038) and around tumors (p=0.0024). Relative BIM-gamma expression was significantly higher in patients with BIM deletion polymorphism than among those without BIM deletion polymorphism (p=0.0017). Patients with BIM-. had significantly shorter progression-free survival than those without BIM-. (median: 304 vs. 732 days; p=0.023). Conclusion: Expression of BIM-. mRNA and BIM deletion polymorphism were strongly associated. BIM-. overexpression may have a role in apoptosis related to EGFR-tyrosine kinase inhibitor.