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Copyright ©2008 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Oct 21, 2008; 14(39): 6052-6059
Published online Oct 21, 2008. doi: 10.3748/wjg.14.6052
Overall expression of beta-catenin outperforms its nuclear accumulation in predicting outcomes of colorectal cancers
Worrawit Wanitsuwan, Samornmas Kanngurn, Teeranut Boonpipattanapong, Rassamee Sangthong, Surasak Sangkhathat
Worrawit Wanitsuwan, Teeranut Boonpipattanapong, Surasak Sangkhathat, Tumor Biology Research Group and Department of Surgery, Faculty of Medicine, Prince of Songkla University, Thailand
Samornmas Kanngurn, Tumor Biology Research Group and Department of Pathology, Faculty of Medicine, Prince of Songkla University, Thailand
Rassamee Sangthong, Tumor Biology Research Group and Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Thailand
Author contributions: Sangkhathat S designed the methodology; Wanitsuwan W, Boonpipattanapong T and Kanngurn S performed clinical work and histopathological study; Sangthong R analyzed data.
Supported by The Faculty of Medicine, Prince of Songkla University
Correspondence to: Dr. Surasak Sangkhathat, Tumor Biology Research Group and Department of Surgery, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, 90110 Thailand. surasak.sa@psu.ac.th
Telephone: +66-7445-1401 Fax: +66-7442-9384
Received: July 1, 2008
Revised: August 17, 2008
Accepted: August 24, 2008
Published online: October 21, 2008
Abstract

AIM: To examine the expression of beta-catenin in colorectal cancer and look for association with other clinico-pathological parameters.

METHODS: Tumor samples from 163 cases of colorectal cancer (CRC) who had undergone primary colectomy between May, 1998 and November, 2002 with complete follow-up data for either 5 years or until death were recruited for a beta-catenin immunohistochemical study. The percentage of immunoreacted tumor cells was defined as overall staining density (OSD) and percentage of cells having nuclear localization was counted as nuclear staining density (NSD). Univariate exploration used log-rank test and multivariate survival analysis used Cox’s hazard regression model.

RESULTS: Beta-catenin immunoreactivity was detected in 161 samples (98.8%), of which 131 cases had nuclear staining. High OSD (≥ 75%), detected in 123 cases (75.5%), was significantly associated with earlier clinical staging (P < 0.01), lower nodal status (P = 0.02), non-metastatic status (P < 0.01) and better differentiation (P = 0.02). Multivariate analysis found that high OSD was independently associated with better survival [Cox’s hazard ratio 0.51, 95% confidence interval (CI) 0.31-0.83]. Although high NSD (≥ 75%) was correlated with high pre-operative serum CEA (P = 0.03), well differentiation (P < 0.01), and increased staining intensity (P < 0.01), the parameter was not significantly associated with survival.

CONCLUSION: Unlike previous reports, the study did not find a predictive value of nuclear beta-catenin in CRC. Instead, the overall expression of beta-catenin in CRC showed an association with better differentiation and earlier staging. Moreover, the parameter also independently predicted superior survival.

Keywords: Colorectal carcinoma; beta-catenin; CTNNB1; Wnt-signaling pathway; Prognosis