Ki-67 expression in relation to clinicopathological variables and prognosis in colorectal adenocarcinomas.

Ki-67 is a protein associated with cell proliferation which is expressed in all phases of the cell cycle except Go. In the present study, Ki-67 expression in 255 human colorectal adenocarcinomas was examined using immunohistochemistry with the monoclonal antibody MIB-1. One hundred and fifty-seven (62%) cases had more than 50% positive tumour cells and 98 (38%) cases less than 50%. The tumours showed a wide range of Ki-67 expression, from 13% to 90%, which indicated a variation in proliferative activity. There was no significant relationship between Ki-67 expression and sex, age, tumour location, Dukes' stage, growth pattern, differentiation, DNA content, S-phase fraction or survival (p > 0.05). In conclusion, the proliferative activity as measured by Ki-67 antibody was not related to clinicopathology and prognosis in colorectal cancer.