CD31 QUANTITATIVE IMMUNOCYTOCHEMICAL ASSAYS IN BREAST CARCINOMAS - CORRELATION WITH CURRENT PROGNOSTIC FACTORS

The distribution of PECAM-1/CD31 molecule was investigated in 133 brea st carcinomas using monoclonal antibody and frozen sections. Anti-CD31 labels endothelial cells and reflects stromal angiogenesis. The CD31 immunoreactivity was evaluated by computer-assisted analysis of digiti zed microscopic images. The automatic screening of the whole preparati on and the measurements of the mean CD31 immunostained surface was per formed in each case. A similar procedure was achieved for p53, catheps in D, P-gp, pHer-2/neu, Ki67, pS2 estrogen and progesterone antigenic sites immunodetection. The image analysis of positive CD31 surface was variable, ranging from 4% to 33% (mean 14.7%, SD = 5.43). The CD31 po sitive surface correlated (P < .01) with the Nottingham prognostic ind ex, but not with the tumor size, the node status, the tumor grade, nor with the patient age. Also the CD31 immunoreactivity was independent of the pHER-2/neu, Ki67 antigen, p53, ER, PR and pS2 immunodetectable expression in tumors, but correlates with that of cathepsin D (P = .02 4) and P-gp (P = .028), which reflects the multi-drug resistance capac ity of tumor cells. In conclusion, CD31 positive vessels assessed on f rozen sections by image analysis constitute an excellent method of eva luating tumor stromal angiogenesis, and can be further used for clinic al purposes. The results also suggest that the CD31/PECAM molecule may be involved in the spread of tumor by interacting with extracellular matrix lysis that results from the tumor cell proteasic activity and w ith multidrug resistance.