Nucleolar Organizer Regions in Myofibroblasts in Breast Cancer: Relation to Cancer Cell Morphometry, Flow Cytometry, Sex Steroid Receptor Content, Tumour Histology and Prognosis

Abstract

The number of silver-stained nucleolar organizer regions (Ag-NORs) was counted in stromal myofibroblasts in 125 cases of breast cancer. The mean (S.E.) of Ag-NORs in stromal myofibroblasts was 4.4 (0.1). The number of Ag-NORs in myofibroblasts was related to histological grade (p = 0.028), histological type (p = 0.013), tumour necrosis (p = 0.026), mitotic frequency (p = 0.091) and S-phase fraction (p = 0.032). The number of Ag-NORs in stromal myofibroblasts predicted survival with a borderline significance (x2 = 3.4, p = 0.052) and also in axillary lymph node negative tumours (X2 = 2.8, p = 0.095). The recurrence-free survival in the entire cohort (X2 = 7.1, p = 0.0075) and in axillary lymph node negative tumours (X2 = 7.1, p = 0.0078) could be predicted on the basis of the number of Ag-NORs in stromal myofibroblasts. In axillary lymph node positive tumours the number of Ag-NORs in stromal myofibroblasts had no prognostic value. In multivariate analysis the number of Ag-NORs in stromal myofibroblasts had no independent prognostic value. The results suggest a close interaction between stromal myofibroblasts and epithelial cancer cells in breast cancer, and stromal changes are clearly a subject for further analyses.