Ki-67 proliferating index and histological grade, type and stage of colorectal carcinoma.

Abstract

BACKGROUND: The objective of this study was to assess the relationship of histological type, grade and stage of colorectal carcinoma with proliferative activity as measured by Ki-67 LI. It was a descriptive study and conducted at the Department of Pathology, University of Health Sciences, Lahore. METHODS: Ki-67 is a protein associated with cell proliferation and is expressed in all the phases of cell cycle except G0. In the present study, Ki-67 expression in 50 patients with colorectal adenocarcinomas was observed using immunohistochemistry with monoclonal antibody MIB-1. RESULTS: Ki-67 LI was high in well and moderately differentiated adenocarcinomas (mean Ki-67 LI 392.50 +/- 56.58 and 342.24 +/- 96.84 respectively) as compared to poorly differentiated adenocarcinomas (mean Ki-67 LI 250.00 +/- 113.46). Ki-67 LI was high in non mucinous adenocarcinomas than mucin secreting and signet ring cell adenocarcinomas (mean Ki-67 393.93 +/- 55.91 vs 220.00 +/- 49.72 and 200.00 +/- 79.05 respectively). As regard the Dukes' staging, Ki-67 LI was high in colorectal carcinomas in Dukes' stage B than tumours in Dukes' stage C (Mean Ki-67 LI 360.13 +/- 90.03 vs 241.66 +/- 101.31 respectively). CONCLUSION: The proliferative activity as measured by Ki-67 antibody is related to histological type, grade and stage.