EGFR tyrosine kinase inhibitor (TKI) in patients with advanced non-small cell lung cancer (NSCLC) harboring uncommon EGFR mutations: A real-world study in China.

Introduction: There are a number of uncommon EGFR mutations whose associations with TKIs are not well clarified. Here, we summarize the clinical data of patients with multiple uncommon EGFR mutations and their sensitivity to EGFR TKIs.

Methods: Between January 2009 and September 2014, we retrospectively examined stage IIIB/IV NSCLC patients harboring uncommon mutations in EGFR at the Shanghai Chest Hospital.

Results: A total of 123 NSCLC patients harboring uncommon EGFR mutations with treatment and survival details were included in this analysis. 95 Patients who received therapy that consisted of EGFR TKIs experienced a significantly improved overall survival (OS) compared with those who did not receive EGFR TKIs (18.96 months, 95% CI, 16.65-21.26 vs 12.22, 95% CI, 9.17-15.27, p=0.017). The median progression-free survival (PFS) for patients who harbored the L861Q, G719X, 20ins, Del-19+L858R, Del-19 or L858R+T790M, and the Del-19 or L858R+other mutations were 8.90 months (95% CI, 4.47-13.34), 5.98 months (95% CI, 1.53-10.42), 2.00 months (95% CI, 0.00-5.41), 9.53 months (95% CI, 0.00-19.41), 1.94 months (95% CI, 0.00-4.43), and 9.79 months (95% CI, 0.73-18.85), respectively. The best objective response rates (ORRs) for patients who harbored L861Q, G719X, 20ins, Del-19+L858R, Del-19 or L858R+T790M, Del-19 or L858R+others were 46.7%, 42.9%, 8.3%, 71.4%, 22.2%, and 55.6%, respectively.

Conclusions: These results suggest that EGFR TKI therapy is effective in patients with L861Q/G719X/Del-19+L858R/Del-19 or L858R+other mutations; less effective in patients with 20ins/Del-19 or L858R+T790M.