Expression of the apoptosis suppressing protein bcl-2 in prostatic adenocarcinoma is related to tumor malignancy.
BACKGROUND
The expression of bcl-2 protein has been related to histopathological features and prognosis in several epithelial tumors. In prostatic adenocarcinoma the prognostic significance of bcl-2 expression is mainly unexplored.


METHODS
The expression of bcl-2 protein was assessed in 235 prostatic adenocarcinomas by using monoclonal bcl-2 protein antibody after microwave pretreatment of the cancer sections. The results of immunohistochemistry were related to histopathological features and prognosis of the patients.


RESULTS
71% of the tumors were bcl-2 negative, in 18% of cases the expression was weak, and in 11% of cases strong. The fraction of bcl-2 positive cells was variable (mean [SE]: 15 [2]%). The expression of bcl-2 protein was positively correlated to high T-category, metastatic disease, and poor histological differentiation of the tumor. Tumors that were aneuploid and rapidly proliferating frequently expressed bcl-2 protein, while tumors we densely infiltrated by inflammatory cells rarely expressed bcl-2. The expression of bcl-2 protein was related to lowered survival probability in univariate analysis, while in multivariate analysis the expression of bcl-2 had no independent prognostic value.


CONCLUSIONS
The expression of bcl-2 protein in prostatic adenocarcinoma is related to tumor malignancy, but the prognostic significance of the expression requires further analyses, particularly in localized tumors.
Lipponen
P
P
Department of Pathology, University of Kuopio, Finland.
Vesalainen
S
S
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D012307:Risk Factors; D016019:Survival Analysis
D014408:Biomarkers, Tumor; D019253:Proto-Oncogene Proteins c-bcl-2