CORRELATION BETWEEN IMMUNOHISTOCHEMICAL EXPRESSION OF PROLIFERATING CELL NUCLEAR ANTIGEN AND FLOW-CYTOMETRY PARAMETERS IN COLORECTAL NEOPLASIA

PURPOSE: Proliferating cell nuclear antigen immunohistochemical expres sion and flow cytometry techniques were used in this study to estimate the proliferation tendency and biologic aggressiveness in benign and malignant epithelial tumors of the colon and rectum. METHODS: Thirty-f ive adenomas and GO adenocarcinomas were studied immunohistochemically concerning proliferating cell nuclear antigen positivity in tumor cel l nuclei. In addition, flow cytometry techniques were used to estimate the DNA content and percentage of tumor cells in the S-phase. RESULTS : The mean proliferating cell nuclear antigen score for adenomas was 3 8 percent compared with a mean score of 50.4 percent for adenocarcinom as that were studied (P < 0.05). In dysplastic areas of malignantly tr ansformed adenomas (n = 5), the highest proliferating cell nuclear ant igen score (80 percent) was focally observed. Taking flow cytometry pa rameters into account, we found out that proliferating cell nuclear an tigen can be used as an indirect indicator of the number of cells in t he S-phase (SPE) but not as an independent prognostic factor. Statisti cal significance was found between Type III (aneuploid carcinomas) and increased proliferating cell nuclear antigen expression (proliferatin g cell nuclear antigen score greater than or equal to 60 percent). Fur thermore, aneuploidy was especially found on cancer located on the lef t colon (44 percent vs. 14 percent of right colon neoplasms). Consider ing DNA ploidy of the above neoplasms, the aneuploid adenocarcinomas h ad a tendency for poorer prognosis especially if they were related to Dukes Stage C female patients. CONCLUSIONS: The comparative assessment of the above parameters might be of considerable importance in the st udy of the proliferation activity of any form of colorectal neoplasia.