Clinical significance of double staining of MIB-1 and AgNORs in primary breast carcinoma.

BACKGROUND Argyrophilic nucleolar organizer regions (AgNORs) and MIB-1 as proliferating activities have been applied separately to assess the malignant potential of cancer cells. We conducted staining of AgNORs and MIB-1 in 42 surgically-resected invasive breast carcinomas. MATERIALS AND METHODS Paraffin-embedded sections were used for double staining and the mean AgNOR counts in 100 MIB-1-positive and -negative cells were calculated. RESULTS The mean AgNOR count in MIB-1-positive cells was significantly higher than in MIB-1-negative ones. AgNOR counts in MIB-1-positive tumors were significantly higher in tumors > or =2 cm and those with positive nodes. Multivariate analysis identified the AgNOR count in MIB-1-positive tumors as the only independent factor related to node metastasis. Survival of patients with lower counts of AgNORs in MIB-1-positive tumors was significantly better compared to those with higher counts. CONCLUSION Double staining of MIB-1 and AgNORs is useful for predicting lymph node metastasis and prognosis of patients with breast carcinoma.