Prognostic value of a proliferation index including MIB1 and argyrophilic nucleolar organizer regions proteins in node-negative breast cancer.

Objective: This study was designed to evaluate a cell proliferation marker, including the percentage of cycling cells (MIB1), and the duration of the cell cycle (assessed by argyrophilic nucleolar organizer regions proteins [AgNORs] measurement).

Study Design: We included 90 patients with invasive node-negative breast cancer. None received chemotherapy. With the help of a double-staining technique, a proliferation index (PI) was determined by multiplying the percentage of MIB1-positive cells by the mean area of the AgNORs present in those MIB1-positive cells. PI was evaluated for its impact on overall survival (OS) and disease-free survival (DFS).

Results: We demonstrated that PI was correlated to OS. For DFS, it conserved its high prognostic value only in univariate analysis. The global amount of AgNORs was more discriminative for DFS.

Conclusion: PI and AgNOR quantification supplied additional prognosis information in node-negative patients, and we propose to integrate them in further studies.