CORRELATION OF AG-NOR PROTEIN MEASUREMENTS WITH PROGNOSIS IN CANINE TRANSMISSIBLE VENEREAL TUMOR

Ten canine transmissible venereal tumour (TVT) cases were studied by d igital image analysis quantification on sections stained with silver t o demonstrate nucleolar organizer regions (Ag-NORs). In each animal, 1 00 neoplastic cells were randomly selected for evaluation. The followi ng parameters were measured or calculated: area of nucleus, area of Ag -NOR dot, the mean number of Ag-NOR dots per nucleus, the mean area of Ag-NOR dots per nucleus and the ratio of mean nuclear dot area to nuc lear area. All 10 cases were treated with vincristine at a dose of 0 . 6 mg/m(2) intravenously once a week. Two, which showed malignant char acteristics (i.e. uncontrolled growth, local invasion or metastasis), did not respond to multiple (12) treatments and had a fatal outcome. O f the remaining eight cases, seven responded to two to six treatments and one required 12 treatments. The average number of Ag-NORs per nucl eus and the area of Ag-NORs per nucleus were lower in the seven cases that responded to two to six treatments than in the other three cases, but the difference was not significant. However, there was a signific ant difference in the ratios of Ag-NOR area to nuclear area between th e two groups of cases. Thus, poor prognosis was (1) possibly correlate d with an increase in the mean number of Ag-NORs per nucleus and an in crease in the mean area of Ag-NORs per nucleus, and (2) definitely cor related with an increase in the mean ratio of Ag-NOR area to nuclear a rea.