PROGNOSTIC-SIGNIFICANCE OF TUMOR-CELL PROLIFERATION RATE AS DETERMINED BY THE MIB-1 ANTIBODY IN BREAST-CARCINOMA - ITS RELATIONSHIP WITH VIMENTIN AND P53 PROTEIN

The prognostic value of tumor cell proliferative activity as measured by the MLB-1 monoclonal antibody in invasive ductal not otherwise spec ified breast carcinomas was determined for 186 patients, including 111 with no axillary node involvement, The MIB-1 antibody detects the Ki- 67 antigen in microwave-processed paraffin sections of the formalin-fi xed tumors. The mean MIB-1 score was 16% for all tumors, 16% for the n ode-negative group, and 15% for the node-positive group, In univariate survival analysis, the MIB-1 score (dichotomized, less than or equal to 10 versus greater than or equal to 10%) predicted overall 5-year su rvival in all of these groups, The mean MIB-1 score was significantly higher in vimentin- and p53 protein-positive tumors (P > 0.001) than i n negative ones. The impact of vimentin expression and of p53 positivi ty on the prognostic significance of the tumor cell proliferation rate was assessed, Vimentin was associated significantly with poor 5-year survival in the entire cohort, and a particularly strong association w as found in the node-negative group, p53 had a weak but statistically nonsignificant influence on survival, In a multivariate analysis using the Cox proportional hazards model, vimentin (P = 0.0002) was the onl y independent prognostic factor in node-negative patients, In contrast , the MIB-1 score (P = 0.009) was the only independent prognostic fact or in the node-positive group, Therefore, node-negative patients with vimentin-positive tumors and node-positive patients with tumors with h igh proliferation rates might be appropriate candidates for early adju vant chemotherapy.