DNA ploidy and nuclear morphometric variables for the evaluation of melanocytic tumors in dogs and cats.
OBJECTIVE
To determine the prognostic importance of the DNA content and nuclear morphometric variables in melanocytic tumors of cats and dogs.


METHODS
27 melanocytic tumors of dogs and cats.


METHODS
Biopsy specimens were investigated by quantitative image analysis after the Feulgen staining method. The DNA content (index), nuclear diameter, ploidy balance, proliferation index, hyperploidy, and growth fraction (Ki67) were measured. Using 1-way ANOVA and a Pearson correlation test, the relationships between the different variables were tested. Their role in the prognosis in affected dogs and cats was estimated using the Cox regression test with respect to 6 months postoperative survival rate.


RESULTS
Significant correlations were found between DNA index and ploidy balance and proliferation index. A significant correlation was also found between hyperploidy and DNA index, and between ploidy balance and proliferation index. Significant differences were found between histologically malignant and benign melanocytic tumors but not between primary malignant tumors and metastatic malignant tumors for DNA index and ploidy balance. No correlation was found between DNA variables and survival time.


CONCLUSIONS
In melanocytic tumors of cats and dogs, DNA index and ploidy balance can be used to differentiate histologically benign from malignant tumors. However, DNA content and nuclear morphometric variables have little value in predicting survival time. The DNA index and ploidy balance provide an additional tool to evaluate melanocytic tumors of cats and dogs. Survival in dogs and cats with melanocytic tumors, however, is not determined by modifications of DNA content or changes in nuclear morphometry of tumor cells.
Roels
S L
SL
Department of Biocontrol, Veterinary and Agrochemistry Research Centre, Brussels, Belgium.
Van Daele
A J
AJ
Van Marck
E A
EA
Ducatelle
R V
RV
D000818:Animals; D001706:Biopsy / Q000662:veterinary; D002371:Cat Diseases / Q000235:genetics* / Q000473:pathology; D002415:Cats; D004273:DNA, Neoplasm / Q000737:chemistry*; D003720:Densitometry / Q000662:veterinary; D004283:Dog Diseases / Q000235:genetics* / Q000473:pathology; D004285:Dogs; D008545:Melanoma / Q000235:genetics / Q000473:pathology / Q000662:veterinary*; D011003:Ploidies
D004273:DNA, Neoplasm