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Int J Clin Exp Pathol 2013;6(12):2846-2854

Original Article
Elevated expression of SOX2 and FGFR1 in correlation with poor prognosis in patients
with small cell lung cancer

Fang Yang, Yina Gao, Jingshu Geng, Di Qu, Qiuyue Han, Jiping Qi, Gongyan Chen

Department of Respiratory Medical Oncology, The Tumor Hospital Affiliated Harbin Medical University, Harbin, China; Department of Pathology,
The Tumor Hospital Affiliated Harbin Medical University, Harbin, China; Department of oncology, The Second Affiliated Hospital of Harbin
Medical University, Harbin, China; Department of Pathology, The First Affiliated Hospital of Harbin Medical University, Harbin, China

Received October 13, 2013; Accepted November 7, 2013; Epub November 15, 2013; Published December 1, 2013

Abstract: Objectives: The central issue in this study is to investigate the expression of Sex determining region Y-BOX2 (SOX2) and fibroblast
growth factor receptor 1 (FGFR1), evaluate their clinicopathological variables and prognostic significance in small cell lung cancer (SCLC).
Methods: Specimens from 222 SCLC patients and 53 adjacent normal lung tissues were detected by the immunohistochemistry for SOX2 and
FGFR1 expression. The relationship between the expression of both markers and survival status was determined. Results: Overexpression of
SOX2 and FGFR1 were revealed in SCLC tumors than in normal tissues (P<0.05). SOX2 expression was associated with clinical stage
(P=0.014) and lymph node status (P=0.041). Besides, FGFR1 expression was significantly higher in ever smokers (P=0.030) and late stage
SCLC (P=0.005). SOX2, FGFR1 and TNM stage were independent prognostic factors for overall survival (OS) and Recurrence-free survival
(RFS) by multivariate analysis. In stage I patients, only overexpression of SOX2, but not of FGFR1, predicted poor OS (0.027) and RFS
(P=0.013). According to the expression of SOX2 and FGFR1, patients were categorized into three groups. Patients with elevated expression of
both markers belonged to the group with the shortest RFS (P<0.0001) and OS (P<0.0001). Conclusions: Increased expression of SOX2 and
FGFR1 may be available as poor prognostic indicators in SCLC patients. (IJCEP1310035).

Keywords: SOX2, FGFR1, small cell lung cancer, immunohistochemistry, prognosis

Address correspondence to: Gongyan Chen, Department of Respiratory Medical Oncology, The Tumor Hospital Affiliated Harbin Medical
University, No. 150, Haping Road, Nangang District, Harbin 150081, China. Tel: +86-451-86298259; Fax: +86-451-86298700; E-mail:
chengongyan@medmail.com.cn