Proliferative activity in invasive breast carcinoma: a comprehensive comparison of MIB-1 immunocytochemical staining in aspiration biopsies to image analytic, flow cytometric and histologic parameters.

OBJECTIVE: To use MIB-1 antibody to assess proliferative activity in fine needle aspiration (FNA) samples of invasive breast carcinoma and compare these results to multiple other measures of proliferative activity. STUDY DESIGN: FNA slides from 62 patients with invasive breast carcinoma were subjected to staining with MIB-1. Quantitative MIB-1 values were compared to image analytic proliferative fractions (IPF) obtained from the same FNAs. MIB-1 values were also compared to flow cytometric S-phase fractions (SPF) and S + G2/M-phase fractions (FPF) and to histologic assessment of mitotic count (MC) in resected tumors. RESULTS: MIB-1 values, IPF, SPF, FPF and MC were suitable for evaluation in 55, 53, 50, 50 and 56 cases, respectively. MIB-1 values showed good correlation with IPF in FNAs (correlation coefficient = .57, P <.00001). MIB-1 values also showed correlation with SPF (correlation coefficient =.447, P = .003), FPF (correlation coefficient = .325, P = .023) and MC (correlation coefficient = .402, P = .01) in resected tumors. CONCLUSION: This study supports the use of MIB-1 values obtained from FNA samples for assessment of proliferative activity in invasive breast carcinoma, based on correlation of these values with multiple other parameters of proliferative activity. Assessment of these values can play a role in predicting prognosis and in selecting patients with invasive carcinoma of the breast for preoperative or adjuvant chemotherapy.