The Prognostic Significance of FGFR4 Gly388 Polymorphism in Esophageal Squamous Cell Carcinoma after Concurrent Chemoradiotherapy

PURPOSE: The purpose of this study is to investigate the role of fibroblast growth factor receptor 4 (FGFR4) polymorphism in esophageal cancer after chemoradiotherapy (CRT). MATERIALS AND METHODS: Peripheral blood samples from 244 patients treated with CRT for esophageal squamous cell carcinoma were assessed for the role of FGFR4 genotype on treatment response and survival. RESULTS: A total of 94 patients were homozygous for the Gly388 allele, and 110 were heterozygous and 40 homozygous for the Arg388 allele. No significant association was found between the FGFR4 genotype and clinicopathological parameters. However, patients carrying the Gly388 allele showed a better overall response rate than Arg388 carriers (p=0.038). In addition, Gly388 allele patients at an earlier stage showed better overall survival (OS) and progression-free survival than Arg388 carriers. Among these, the Gly388 allele showed significantly improved OS compared to Arg388 carriers in the lymph node (LN) metastasis group (p=0.042) compared to the no LN metastasis group (p=0.125). However, similar survival outcomes were observed for advanced-stage disease regardless of genotype. CONCLUSION: This result suggests that the role of FGFR4 Gly388 in treatment outcomes differs according to esophageal cancer stage. It showed a predictive role in the response of esophageal cancer patients to CRT with a better trend for OS in Gly388 than Arg388 carriers in the early stages. In particular, LN-positive early-stage patients carrying the Gly388 allele showed improved OS compared to those carrying Arg388.