Open Access Highly Accessed Research article

CD133 expression is not an independent prognostic factor in stage II and III colorectal cancer but may predict the better outcome in patients with adjuvant therapy

Khalilullah Mia-Jan1, So Young Jung1, Ik-Yong Kim2, Sung Soo Oh3, EunHee Choi4, Sei Jin Chang35, Tae Young Kang1 and Mee-Yon Cho16*

Author Affiliations

1 Department of Pathology, Yonsei University Wonju College of Medicine, Wonju, South Korea

2 Department of Surgery, Yonsei University Wonju College of Medicine, Wonju, South Korea

3 Department of Occupational and Environmental Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea

4 Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea

5 Preventive Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea

6 Institute of Genomic Cohort, Yonsei University Wonju College of Medicine, Wonju, Korea

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BMC Cancer 2013, 13:166  doi:10.1186/1471-2407-13-166

Published: 28 March 2013

Abstract

Background

Cancer stem cells (CSCs) are notorious for their capacity of tumor progression, metastasis or resistance to chemo-radiotherapy. However, the undisputed role of cancer stem marker, CD133, in colorectal cancers (CRCs) is not clear yet.

Methods

We assessed 271 surgically-resected stage II and III primary CRCs with (171) and without (100) adjuvant therapy after surgery. CD133 expression was analyzed by immunohistochemical (IHC) staining and real-time RT-PCR. CD133 promoter methylation was quantified by pyrosequencing.

Results

The CD133 IHC expression was significantly correlated with mRNA expression (p=0.0257) and inversely correlated with the promoter methylation (p=0.0001). CD133 was expressed more frequently in rectal cancer (p=0.0035), and in moderately differentiated tumors (p=0.0378). In survival analysis, CD133 expression was not significantly correlated with overall survival (OS) (p=0.9689) as well as disease-free survival (DFS) (p=0.2103). However, CD133+ tumors were significantly associated with better OS in patients with adjuvant therapy compared to those without adjuvant therapy (p<0.0001, HR 0.125, 95% CI 0.052-0.299). But the patients with CD133- tumors did not show any significant difference of survival according to adjuvant therapy (p=0.055, HR 0.500, 95% CI 0.247-1.015).

Conclusions

In stage II and III CRCs, CD133 IHC expression may signify the benefit for adjuvant therapy although it is not an independent prognostic factor.

Keywords:
Cancer stem cell; CD133 protein; Human; Colorectal neoplasms; Immunohistochemistry; Chemoradiotherapy; Adjuvant; Prognosis