Original Article


RELATIONSHIP BETWEEN PROLIFERATING CELL NUCLEAR ANTIGEN EXPRESSION AND ITS MALIGNANCY POTENTIAL IN COLORECTAL CARCINOMA

Xiaowei Xiao

Abstract

Objective: To study the relationship between proliferating cell nuclear antigen expression and its malignancy potential in colorectal carcinoma.
Methods: Paraffin sections of 86 patients with advanced coiorectal carcinoma were assessed by immunohistochemical study, using a mouse monoclonal antibody (pc-10, DAKO Co. USA) to check proliferating cell nuclear antigen (PCNA). To compare PCNA with conventional clinicopathologic factor, including p53 overexpression, tissue carcinoembnyonic antigen immunoreactivity pattern and flow cytometric DNA ploidy for assessing tumor malignancy potential. In addition, recurrence and survival of patients with advanced colorectal carcinoma after curative resection were analyzed in accordance with degree of PCNA expression.
Results: PCNAlabeling index (PCNA-LI) increased significantly as the tumor stage advanced (p=0.0001). Strong correlations were observed between PCNA-LI and various pathologic parameters, including histologic differentiation (P=0.0027), lymphatic invasion (P=0.0001), vascular invasion (P=0.0001), lymph node metastasis (P=0.0001), and liver metastasis (P=0.0036). Mean PCNA-LI was also significantly higher in tumor with DNA aneuploidy (P=0.0006) and negative (P=0.01). Linear relationships were demonstrated between PCNALI and clinical outcomes; Recurrence rate was significantly greater in the group with higher than the mean PCNA-LI, who underwent curative resection (P<0.01), and three-year survival rates for curative cases with higher than the mean PCNA-LI were significantly poorer than those with lower than mean PCNA-LI (P<0.005).
Conclusion: There were correlations between PCNA-LI and various pathologic parameters, PCNA-LI increased significantly as the tumor stage advanced in colorectal carcinoma, the rates of recurrence and death got higher as PCNA-LI increased after curative resection for colorectal carcinoma.