Brief Article
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World J Gastroenterol. Mar 7, 2013; 19(9): 1438-1443
Published online Mar 7, 2013. doi: 10.3748/wjg.v19.i9.1438
CD24 expression predicts distant metastasis in extrahepatic bile duct cancer
Kyubo Kim, Hye Sook Min, Eui Kyu Chie, Jin-Young Jang, Sun Whe Kim, Sae-Won Han, Do-Youn Oh, Seock-Ah Im, Tae-You Kim, Yung-Jue Bang, Ja-June Jang, Sung W Ha
Kyubo Kim, Eui Kyu Chie, Sung W Ha, Department of Radiation Oncology, Seoul National University College of Medicine, Seoul 110-744, South Korea
Hye Sook Min, Ja-June Jang, Department of Pathology, Seoul National University College of Medicine, Seoul 110-744, South Korea
Jin-Young Jang, Sun Whe Kim, Department of Surgery, Seoul National University College of Medicine, Seoul 110-744, South Korea
Sae-Won Han, Do-Youn Oh, Seock-Ah Im, Tae-You Kim, Yung-Jue Bang, Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744, South Korea
Eui Kyu Chie, Sung W Ha, Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul 151-742, South Korea
Author contributions: Kim K and Min HS contributed equally to this work; Kim K, Min HS and Chie EK designed the research; Kim K, Min HS, Chie EK, Jang JY, Kim SW, Han SW, Oh DY, Im SA, Kim TY, Bang YJ, Jang JJ and Ha SW performed the research; Kim K analyzed the data; and Kim K, Min HS and Chie EK wrote the paper.
Supported by Seoul National University Hospital Research Fund, No. 04-2010-0940
Correspondence to: Eui Kyu Chie, MD, Department of Radiation Oncology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, South Korea. ekchie93@snu.ac.kr
Telephone: +82-2-20723705 Fax: +82-2-7653317
Received: September 23, 2012
Revised: December 26, 2012
Accepted: January 5, 2013
Published online: March 7, 2013
Abstract

AIM: To evaluate the prognostic significance of CD24 expression in patients undergoing adjuvant chemoradiotherapy for extrahepatic bile duct (EHBD) cancer.

METHODS: Eighty-four patients with EHBD cancer who underwent curative resection followed by adjuvant chemoradiotherapy were enrolled in this study. Postoperative radiotherapy was delivered to the tumor bed and regional lymph nodes up to a median of 40 Gy (range: 40-56 Gy). All patients also received fluoropyrimidine chemotherapy for radiosensitization during radiotherapy. CD24 expression was assessed with immunohistochemical staining on tissue microarray. Clinicopathologic factors as well as CD24 expression were evaluated in multivariate analysis for clinical outcomes including loco-regional recurrence, distant metastasis-free and overall survival.

RESULTS: CD24 was expressed in 36 patients (42.9%). CD24 expression was associated with distant metastasis, but not with loco-regional recurrence nor with overall survival. The 5-year distant metastasis-free survival rates were 55.1% and 29.0% in patients with negative and positive expression, respectively (P = 0.0100). On multivariate analysis incorporating N stage, histologic differentiation and CD24 expression, N stage was the only significant factor predicting distant metastasis-free survival (P = 0.0089), while CD24 expression had borderline significance (P = 0.0733). In subgroup analysis, CD24 expression was significantly associated with 5-year distant metastasis-free survival in node-positive patients (38.4% with negative expression vs 0% with positive expression, P = 0.0110), but not in node-negative patients (62.0% with negative expression vs 64.0% with positive expression, P = 0.8599).

CONCLUSION: CD24 expression was a significant predictor of distant metastasis for patients undergoing curative resection followed by adjuvant chemoradiotherapy especially for node-positive EHBD cancer.

Keywords: CD24, Tissue microarray, Extrahepatic bile duct cancer, Adjuvant chemoradiotherapy, Distant metastasis