High coexpression of both insulin-like growth factor receptor-1 (IGFR-1) and epidermal growth factor receptor (EGFR) is associated with shorter disease-free survival in resected non-small-cell lung cancer patients

Background: Insulin-like growth factor receptor-1 (IGFR-1) represents a novel molecular target in non-small-cell lung cancer (NSCLC). IGFR-1 and epidermal growth factor receptor (EGFR) activation is essential to mediate tumor cell survival, proliferation and invasion. We explored the correlation between IGFR-1 and EGFR, their relationship with clinicopathological parameters and their impact on outcome in resected stage I-III NSCLC patients. Patients and methods: Tumors from 125 surgical NSCLC patients were evaluated for IGFR-1 and EGFR expression by immunohistochemistry. Kaplan-Meier estimates of survival and time to recurrence were calculated for clinical variables and biologic markers using the Cox model for multivariate analysis. Results: IGFR-1 protein overexpression was detected in 36.0% of NSCLC patients and was associated with larger tumor size (P = 0.04) but not with other clinical or biological characteristics. EGFR protein overexpression was observed in 55.2% of NSCLC, more frequently in squamous cell carcinoma (SCC) than non-SCC (63.7% versus 36.3%, chi(2) = 9.8, P = 0.001). IGFR-1 protein expression was associated with EGFR protein expression (P = 0.03). At the multivariate analysis, high coexpression of both IGFR-1 and EGFR was a significant prognostic factor of worse disease-free survival (DFS) (hazard ratio 2.51, P = 0.01). Conclusion: A statistically significant association was observed between high coexpression of both IGFR-1 and EGFR and worse DFS in early NSCLC patients.