The c-erbB-2 gene is located on q21 of chromosome 17. The c-erbB-2 oncoprotein exhibits tyrosine kinase activity, appears to be a receptor for an yet unidentified growth factor and has been demonstrated in a number of cancers by
immunohistochemical
as
well as matrix blotting techniques. Breast and ovarian cancer patients, whose tumor cells have amplification or overexpression of this oncoprotein, have been suggested to have worse prognosis. But there were only a few reports on c-erbB-2
oncoprotein
expression in prostatic carcinoma. The aim of this study was to examine the c-rbB-2 oncoprotein expression in prostatic adenocarcinoma to assess its potential as a useful prognostic marker in this disease. The samples were considered
immunoreactive
when
distinct cellmembrane was stained. These staining pattern was noted exclusively in neoplastic cells and was uniformly distributed throughout the neoplastic cell population. Incidence of c-erbB-2 oncoprotein expression in Gleason grade 4 and 5
prostatic
adenocarcinoma is significantly higher than that in Gleason grade 1, 2 and 3 (Chi-square test, p<0.05), and incidence in stage D prostatic adenocarcinoma is significantly higher than that in stage A, B and C(Chi-square test, p<0.25). But there is
no
significant difference of c-erbB-2 oncoprotein expression according to DNA ploidy or proliferation index by flow cytometry, High proliferating cell nuclear antigen (PCNA) expression rate is not associated with c-erbB-2 oncoprotein expression.
The results of this study suggest that the c-erbB-2 oncoprotein together with other predictive parameters may serve to provide a phenotypic profile which permits more accurate forecasting of prostatic cancer behavior, and may prove useful in the
future
as an important guide for directing specific anti-tumor therapy. To investigate these possibilities, further studies based on larger numbers of cases with complete follow up data will be needed.
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