Clinicopathological significance of fibroblast growth factor 1 in non–small cell lung cancer

Abstract

Fibroblast growth factor (FGF) 1 is identified as a candidate cancer biomarker in several kinds of cancer. However, little is known about its expression and function in non-small cell lung cancer (NSCLC). The aim of this study is to identify the expression of FGF1 in primary human NSCLC tissues and evaluate its clinical significance for NSCLC patients. Archived tissues from NSCLC (n = 113) and adjacent normal lung tissues (n = 71) were examined for the immunohistochemical expression of FGF1; then we analyzed the correlations of FGF1 expression with clinicopathological factors and overall survival of the patients. FGF1 expression was identified in the cytoplasm or both cytoplasm and nucleus of NSCLC cells. Immunoreactive scores of FGF1 were significantly higher in NSCLC specimens than in peritumoral normal tissues. High expression of FGF1 (immunoreactive score >3) was detected in 61.9% (70/113) of NSCLC specimens, and high FGF1 expression in cancer cells was significantly correlated with larger primary tumor size, squamous cell carcinoma (SQCC), and vascular invasion. In addition, FGF1 expression was correlated with intratumoral microvessel density in both SQCC and adenocarcinoma subgroups. Moreover, NSCLC patients with high FGF1 expression had a significantly lower overall survival rate, compared with those with low FGF1 expression. Furthermore, subgroup analyses showed that FGF1 expression was associated with poor prognosis in lung SQCC, but not in adenocarcinoma. These findings suggest that the presence of FGF1 in NSCLC cells may serve as a prognostic indicator and a potential therapeutic target for NSCLC patients, especially for lung SQCC.