Open Access Research article

Synuclein gamma predicts poor clinical outcome in colon cancer with normal levels of carcinoembryonic antigen

Caiyun Liu1,2†, Bin Dong3†, Aiping Lu3, Like Qu1,2, Xiaofang Xing1,2, Lin Meng1,2, Jian Wu1,2, Y Eric Shi4 and Chengchao Shou1,2*

  • * Corresponding author: Chengchao Shou scc@bjcancer.org

  • † Equal contributors

Author Affiliations

1 Key laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University School of Oncology, 52 Fucheng Road, Haidian District, Beijing 100142, China

2 Department of Biochemistry & Molecular Biology, Peking University School of Oncology, Beijing Cancer Hospital & Institute, 52 Fucheng Road, Haidian District, Beijing 100142, China

3 Department of Pathology, Peking University School of Oncology, Beijing Cancer Hospital & Institute, 52 Fucheng Road, Haidian District, Beijing 100142, China

4 Department of Radiation Medicine, Long Island Jewish Medical Center, The Feinstein Institute for Medical Research, 270-05 76th Avenue, New Hyde Park, NY 11040, USA

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BMC Cancer 2010, 10:359 doi:10.1186/1471-2407-10-359

Published: 7 July 2010

Abstract

Background

Synuclein gamma (SNCG), initially identified as a breast cancer specific gene, is aberrantly expressed in many different malignant tumors but rarely expressed in matched nonneoplastic adjacent tissues. In this study, we investigated the prognostic potential of SNCG in colon cancer particularly in the patients with normal carcinoembryonic antigen (CEA) levels.

Methods

SNCG levels were assessed immunohistochemically in cancer tissues from 229 colon adenocarcinoma patients with a mean follow-up of 44 months. Correlations between SNCG levels and clinicopathologic features, preoperative serum CEA level, and clinical outcome were analyzed statistically using SPSS.

Results

SNCG levels in colon adenocarcinoma were closely associated with intravascular embolus and tumor recurrence but independent of preoperative serum CEA levels. SNCG expression was an independent prognostic factor of a shorter disease-free survival (DFS) and overall survival (OS) (P < 0.0001). Multivariate analysis revealed that both tissue SNCG and serum CEA were independent prognostic factors of DFS (P = 0.001, <0.0001, respectively) for 170 patients with colon adenocarcinomas. Importantly, SNCG remained a prognostic determinant of DFS and OS (P = 0.001, 0.002) for 97 patients with normal preoperative serum CEA level.

Conclusions

Our results suggest for the first time that SNCG is a new independent predicator for poor prognosis in patients with colon adenocarcinoma, including those with normal CEA levels. Combination of CEA with SNCG improves prognostic evaluation for patients with colon adenocarcinoma.