Brief Article
Copyright ©2010 Baishideng. All rights reserved
World J Gastroenterol. Apr 21, 2010; 16(15): 1879-1884
Published online Apr 21, 2010. doi: 10.3748/wjg.v16.i15.1879
Comparative analysis of clinicopathological correlations of cyclooxygenase-2 expression in resectable pancreatic cancer
Marketa Hermanova, Petr Karasek, Jiri Tomasek, Jiri Lenz, Jiri Jarkovsky, Petr Dite
Marketa Hermanova, Jiri Lenz, First Department of Pathologic Anatomy, Medical Faculty of Masaryk University and St. Anne’s University Hospital, 65691 Brno, Czech Republic
Petr Karasek, Jiri Tomasek, Department of Complex Oncology Care, Masaryk Memorial Cancer Institute, 65653 Brno, Czech Republic
Jiri Jarkovsky, Institute of Biostatistics and Analyses, Masaryk University, 62500 Brno, Czech Republic
Petr Dite, Department of Gastroenterology, Medical Faculty of Masaryk University and The Faculty Hospital Brno, 62500 Brno, Czech Republic
Author contributions: Hermanova M coordinated the study and wrote the manuscript; Hermanova M and Lenz J performed histopathological and immunohistochemical examinations of tumors included in the study; Karasek P, Tomasek J and Dite P participated in clinical data acquisition and in analysis and interpretations of results; Jarkovsky J performed the statistical analysis and participated in analysis and interpretation of obtained results.
Supported by A Grant from the Ministry of Health (IGA), No. NR 9295-3, Czech Republic
Correspondence to: Marketa Hermanova, MD, PhD, First Department of Pathologic Anatomy, Medical Faculty of Masaryk University and St. Anne’s University Hospital, Pekarska 53, 65691 Brno, Czech Republic. marketa.hermanova@fnusa.cz
Telephone: +420-54-3183218 Fax: +420-54-3182100
Received: January 5, 2010
Revised: January 26, 2010
Accepted: February 3, 2010
Published online: April 21, 2010
Abstract

AIM: To perform a comparative analysis of clinicopathological correlations of cyclooxygenase-2 (COX-2) expression in pancreatic cancer, examined by monoclonal and polyclonal antibodies.

METHODS: The COX-2 expression in 85 resection specimens of pancreatic ductal adenocarcinoma was immunohistochemically examined using both monoclonal and polyclonal antibodies. The final immunoscores were obtained by multiplying the percentage of positive cells with the numeric score reflecting the staining intensity. COX-2 expression levels were classified into three categories (0, 1+, and 2+) and the clinicopathological correlations were statistically evaluated and analyzed.

RESULTS: The positive tumor expression rates of COX-2 were 80.5% using monoclonal antibody and 69.4% using polyclonal antibody. In the Kaplan-Meier analysis, no significant correlations were found between levels of COX-2 expression and overall survival (OS), but trends to longer OS were found in COX-2 negative cases using monoclonal antibody. Significantly longer disease free survival was revealed in COX-2 negative cases using monoclonal antibody (P = 0.019). No correlations between COX-2 expression levels and grade (G), tumor (T) status and nodal (N) status were demonstrated. Low histological grade showed a strong association with a longer OS (P < 0.001). Correlation of survival and T status revealed a shorter OS in T3 tumors, but the results reached only marginal statistical significance (P = 0.070). In the multivariate Cox proportional hazards regression model, histological grade, T and N status remained valuable predictors of a worse survival with borderline significance for T [hazards ratio (HR) = 4.18 for G (if G = 3, P < 0.001); HR = 1.64 for T (if T = 3, P = 0.065); HR = 2.53 for N (if N = 1, P = 0.006)]. Higher grade, T or N status was associated with a worse OS.

CONCLUSION: The immunohistochemically assessed level of COX-2 expression does not seem to represent a valuable independent prognostic factor and is not superior to the conventional prognostic factors.

Keywords: Pancreatic cancer; Cyclooxygenase-2; Immunohistochemistry; Monoclonal antibody; Polyclonal antibody