Ki-67 antibody labeling index in colorectal carcinoma

Ki-67 labeling index of 58 colorectal carcinomas and 10 normal colonic mucosa samples was determined by the use of an immunohistochemical staining technique. The Ki-67 labeling index in colorectal carcinomas ranged from 15.7 to 63.6% (mean +/- SD of 38.5 +/- 10.5) and was significantly higher than the index for normal colon mucosa (mean +/- SD of 14.1 +/- 2.8). The mean Ki-67 labeling index was significantly higher in Dukes' B and Dukes' C tumors than in Dukes' A tumors, but the index did not correlate with the size of the tumor. There was no correlation between the Ki-67 labeling index of the tumor and lymph node involvement. The present study disclosed that the Ki-67 labeling index correlated with local invasion of colorectal carcinoma, but not with metastasis of the tumor.