Co-expression of aFGF and FGFR-1 is predictive of a poor prognosis in patients with esophageal squamous cell carcinoma

Overexpression of aFGF, bFGF and FGFR-1 has been reported in various cancers, and it has been suggested that it may be a poor prognostic factor in cases with solid tumors. Therefore, we attempted to determine whether overexpression of aFGF, bFGF and FGFR-1 might also be a poor prognostic factor in patients with esophageal squamous cell carcinoma, and examined the expression of aFGF, bFGF and FGFR-1 in esophageal cancer tissue specimens to clarify their clinical significance. Seventy-nine patients with squamous cell carcinoma of the esophagus who underwent resection at the Department of Surgery, Keio University Hospital, were enrolled as the subjects of this study. None of the patients had received any previous treatment. Formalin-fixed and paraffin-embedded sections of esophageal cancer tissue were stained by immunohistochemical methods and examined for expression of the angiogenetic factors and their receptors, and also to determine the microvascular density (MVD). We examined the correlations between the expression of aFGF, bFGF and FGFR-1, and the MVD, clinicopathological background factors and survival of the patients by conducting statistical analyses of the data. The results revealed that positive aFGF expression was associated with a larger tumor area (p=0.009), and co-expression of both aFGF and FGFR-1 was associated with a larger tumor area (p=0.01) and poorer prognosis (p=0.04). There were positive correlations between the expression of aFGF and FGFR-1 (p<0.0001), and between those of bFGF and FGFR-1 (p=0.04). aFGF may promote proliferation of esophageal cancer cells in an angiogenesis-independent and autocrine manner, and may contribute to rapid growth of esophageal cancer on recurrence after esophageal resection.