Nucleolar organizer regions related to morphometry, flow cytometry, sex steroid receptor content, tumour histology and prognosis in female breast cancer.

Nuclear organizer regions (Ag-NORs) were visualized and enumerated in biopsy specimens from 158 breast carcinomas and the results were correlated with clinical, histological, quantitative prognostic factors and survival. The number of Ag-NORs was related significantly to histological type (p = 0.003), tubule formation (p = 0.013), histological grade (p < 0.001), mean nuclear area (p < 0.001), SD of nuclear area (p < 0.001), DNA ploidy (p < 0.001), S phase fraction (p = 0.001), mitotic index (p < 0.001), estrogen receptor content (p < 0.001) and progesterone receptor content (p < 0.001). Ag-NORs were independent of tumour size and axillary lymph node status. Neither in the entire cohort (p = 0.16) nor in axillary lymph node negative tumours (p = 0.11) was the number of Ag-NORs related to survival although a clear trend was observed between lowered survival probability and high Ag-NOR count. In multivariate analysis Ag-NORs had no independent prognostic value. The results confirm previous results in that Ag-NORs have no practical prognostic value over already established prognostic factors in breast cancer.