FGFR1 amplification is associated with poor prognosis and smoking in non-small-cell lung cancer

FGFR1 amplification has been identified recently as an important therapeutic target in non-small-cell lung cancer (NSCLC), particularly squamous cell carcinoma (SqCC). However, data from previous studies on the clinical implications of FGFR amplification in NSCLC are inconsistent. We evaluated FGFR1 gene copy number (GCN) in 369 cases of surgically resected NSCLC using five previously reported criteria and investigated associations between clinicopathologic parameters and FGFR1 amplification. FGFR1 amplification was found in 32/369 (8.7 %) of NSCLC and was more frequent in SqCC (18.0 % in SqCC, 3.0 % in adenocarcinoma; p < 0.001) and in smokers (p < 0.001). On univariate analysis, FGFR1 amplification was significantly associated with shorter overall survival (OS, 58.6 vs 80.0 months; p = 0.033) and shorter disease-free survival (DFS, 58.5 vs 80.0 months; p = 0.042) in patients with SqCC, but this was not statistically significant on multivariate analysis (OS: hazard ratio [HR] = 1.79, 95 % confidence interval [CI] = 0.83–3.87, p = 0.139; DFS: HR = 1.73, 95 % CI = 0.93–3.21, p = 0.081). The correlation between FGFR1 amplification and protein expression was poor (rho = 0.08; p = 0.123). These results suggest that FGFR1 amplification is associated with smoking history and squamous cell carcinoma histology and might indicate poor prognosis.