Overexpression of Fibroblast Growth Factor 8 Is a Predictor of Impaired Survival in Esophageal Squamous Cell Carcinoma and Correlates with ALK/EML4 Alteration.

FGF8, ALK, and EML4 have been identified as promising biomarkers in a number of malignancies. The aim of this study was to examine the prognostic role of FGF8, ALK, and EML4 in esophageal squamous cell carcinoma (ESCC). Methods: Consecutive patients with ESCC who underwent upfront resection were included in this study. ALK and EML4 gene status was evaluated by fluorescence in situ hybridization (FISH) using a triple-color break-apart single-fusion probe and a probe against 2p11. FGF8, ALK, and EML4 protein expression was determined by immunohistochemistry. Results: A total of 122 patients were included in this study. Multivariate analysis revealed that FGF8 overexpression is an independent negative prognostic factor for patients' overall survival (OS) (p = 0.04). Furthermore, a significant correlation between the expression of FGF8, and ALK (p = 0.04) and EML4 (p = 0.01) alteration was found. Conclusions: FGF8 overexpression is an adverse independent prognostic factor in patients with upfront resected ESCC. Furthermore, FGF8 expression significantly correlates with ALK and EML4 amplification and may therefore qualify as a future therapeutic target.