THE EXPRESSION OF C-ERBB2 ONCOGENE PROTEIN AS A PROGNOSTIC FACTOR IN FELINE MAMMARY TUMORS

Abstract

The study looked at the relationship between the expression of c-erbB2 oncogene protein, histological types, PCNA and AgNORs indices, in feline mammary tumors. Sixty, surgically resected, mammary tumors from cats were collected and histological processed. The expression of c-erbB2 oncogene protein was detected by immunohistochemistry and was seen in benign hyperplasia, adenosis and malignant groups. The c-erbB2 oncogene
protein expression in malignant, feline mammary tumors was 41.67% (25/60) which could be divided into simple tubular ACC, 25% (6/24), simple papillary ACC, 78.6% (11/14), solid carcinoma, 26.7% (4/15) and cribiform carcinoma, 57.14% (4/7). There were statistically significantly differences (p<0.05) in the expression of c-erbB2
oncogene protein between simple tubular ACC, compared with simple papillary ACC and solid carcinomas. The expression of c-erbB2 oncogene protein in specimens, classified by histological malignancy grades revealed, grade I, 42.11% and grade II, 41.46% but there was no statistically significant difference between them. An evaluation of a proliferative marker shown by a mean (±SD) of PCNA, was 34.63±23.87 and the mean (±SD) of
AgNORs was 1.23±0.18. There was no significant difference between the PCNA and AgNORs index of both the histological types and the histological malignancy grades. However, a statistical difference of mean PCNA and AgNORs indices was noted in both c-erbB2 positive and c-erbB2 negative groups. The mean PCNA indices and
AgNORs indices in c-erbB2 positive samples were 26.52±18.68 and 1.12±0.27 respectively, while the c-erbB2 negative ones were 39.43±26.24 and 1.28±0.19 respectively. In conclusion, c-erbB2 oncogene protein expression is considered
to be an effective prognostic factor for adenocarcinoma subtypes of feline mammary tumors as it is in human and canine cases. However, integration of all the parameters (c-erbB2 oncogene protein, PCNA index, AgNORs index, histological types and clinical data) may achieve a more precise prognosis in feline, mammary tumor cases.