Objective: To better understand the clinical implications of insulin-like growth factor type 1 receptor (IGF-1R), epidermal growth factor receptor (EGFR) and HER2 expressions in gastric cancer (GC).
Methods: The study group comprised 86 patients who received first-line chemotherapy for advanced GC at the National Cancer Center Hospital. Using laser-captured microdissection and a real-time RT-PCR assay, we quantitatively evaluated mRNA levels of IGF-1R, EGFR and HER2 in paraffin-embedded cancer specimens of surgically removed primary tumors.
Results: In univariate analysis of the study group as a whole, patients with low expression of both IGF-1R and EGFR (n = 13) had a significantly longer overall survival than the other patients (n = 51; median, 24.6 vs. 12.8 months; log-rank p = 0.013). Multivariate survival analysis demonstrated that high EGFR expression [hazard ratio, HR: 2.94 (95% confidence interval, CI: 1.40-6.17), p = 0.004] and poor performance status [HR: 1.96 (95% CI: 1.12-3.42), p = 0.018] were significant predictors of poor survival. In patients given first-line S-1 monotherapy (n = 29), low IGF-1R (p = 0.002) and low EGFR (p = 0.035) gene expression correlated with a better response, without a significant prolongation of survival.
Conclusion: Our data warrant further investigations on the strategy of co-targeting IGF-1R and EGFR in GC.
Copyright 2008 S. Karger AG, Basel.