NUCLEOLAR ORGANIZER REGIONS IN BLADDER-CANCER - APPLICATION TO URINARY CYTOLOGY

Objectives. We investigated the relationship between the numbers of nu cleolar organizer regions (NORs) in nonmalignant reactive cells and th ose in transitional cell carcinomas using urinary exfoliated cell spec imens. Another aim of this study was to determine whether higher numbe rs of NORs are correlated with tumors with higher pathologic grade. Me thods. Nucleolar organizer regions, which are important for regulating protein synthesis, were counted by means of a silver staining techniq ue in urinary exfoliated cells from 34 patients with transitional cell carcinoma (TCC) and in 30 patients with other urologic diseases (cont rols). Results. The number of argyrophilic proteins of the nucleolar o rganizer region (Ag-NORs) per cell (mean +/-SD) was 2.9 +/- 0.5 in the control group and 5.5 +/- 1.9 in patients with TCC, which was signifi cantly higher than that in the controls (p < 0.001). It was 4.0 +/- 1. 0 in patients with grade 1 TCC, 5.4 +/- 2.0 in those with grade 2 TCC, and 6.5 +/- 1.2 in those with grade 3 TCC. Although no statistically significant difference was observed between the groups, the patients w ith grade 2 TCCs with higher numbers of Ag-NORs showed a tendency to h ave more diffuse and/or invasive lesions. Conclusions. This method is simple and quick, and can identify low-grade malignancy. It could be u sed as a tool for further grading of grade 2 TCCs and for determining prognosis.