Background: Many studies concluded that epidermal growth factor receptor (EGFR) gene amplification might be related with the prognosis in non-small cell lung cancer. However, the results were not consistent. To identify whether EGFR gene amplification could affect the prognosis, a meta-analysis was conducted based on the published works.
Methods: According to inclusion and exclusion criteria, articles were selected from medical electronic databases searching, including PubMed, Cochrane library and CNKI. The qualities of included articles were scored based on the European Lung Cancer Working Party scale, and the hazard ratio (HR) and the 95% confidence interval (CI) were also collected. Meta-analysis was completed using software Review Manager 4.2.
Results: Forest plot from 12 studies in which 1 221 included patients were all treated with EGFR-TKI showed that the prognosis of patients harboring EGFR gene amplification were superior to negative ones (HR=0.82, 95%CI: 0.68-0.99, P=0.04), and for Caucasian patients who received EGFR-TKI, the survivals were longer in EGFR gene amplification positive cases than those without amplification (HR=0.42, 95%CI: 0.31-0.57, P<0.001). Meta results from 8 studies in which 658 included patients did not receive EGFR-TKI indicated that the casualty hazard of amplification positive patients was comparable with negative ones. However, for Asia patients who failed to receive EGFR-TKI, the prognosis of patients with EGFR gene amplification were inferior to negative ones (HR=1.88, 95%CI: 1.21-2.93, P=0.005).
Conclusions: EGFR gene amplification may be a positive predictive factor in terms of survival for Caucasian patients receiving EGFR-TKI rather than Asia patients. However, the prognosis was inferior in Asia patients with EGFR amplification to those without the amplification, if they failed to receive EGFR-TKI.