PROGNOSTIC VALUE OF KI 67 MIB1 AUTOMATED AND QUANTITATIVE IMMUNOLABELING IN PRIMARY OPERABLE BREAST CARCINOMAS/

The prognostic significance of Ki 67/MIB1 immunohistochemical assays ( ICAs) was investigated in optimal technical conditions in 139 breast c arcinomas. Automated ICAs (immunoperoxidase/Ventana device) was perfor med on frozen sections. Immunoprecipitates were quantified by computer ized analysis (SAMBA) of digitized microscopic images. Mean positive s urfaces (%) and quantitative immunocytochemical (QIC) index were corre lated to the patients survival (8-year survival). The results showed t hat Ki 67/MIB1 large surfaces (cutpoint, 20%) and high QIC index (cutp oint, 12) correlated with poor overall survival (Kaplan Meier, log ran k test, p=0.011 and p=0.037, BMDP software). In node positive, but not in node negative patients, large Ki 67/MIB1 surface (cutpoint, 20%) a nd high QIC index (cut-off 12) correlated with the overall patient sur vival (p=0.0037 and p=0.049). Also large Ki 67/MIB1 positive surface ( cut-off, 20%) correlated with disease-free survival in all patients an d node positive patients (p=0.022 and p=0.0057) but not in node negati ve patients. It is concluded that in optimal technical conditions (aut omated and quantitative immunohistochemical assays on frozen sections) Ki 67 antigen immunohistochemical expression in breast carcinomas tis sue has a prognostic significance in node positive patients but not in node negative patients.