Bcl-2 expression in primary uveal melanoma

Aims: Uveal malignant melanoma is the most common intraocular tumor. The ai m of this study was the analysis of bcl-2 oncoprotein expression in this tu mor type. The melanomas were evaluated according to tumor location and pati ent age and sex. The relationship between bcl-2 expression and histological type, clinicopathologic stage and the presence of a set of predetermined m orphological parameters was analyzed. Methods: The study involved 39 patients with ocular melanomas treated with surgery alone between 1983 and 1997. Formalin-fixed, paraffin-embedded tiss ues were treated with anti-bcl-2 antibody (Dako No M0887). Immunolocalizati on of the bcl-2 oncoprotein was performed using the labeled streptavidin bi otin (LSAB) method. bcl-2 expression in neoplastic cells was evaluated in a semiquantitative manner: lack of reactivity was defined as bcl-2 negative, reactivity present in less than 30% of cells as low bcl-2, end reactivity in more than 30% of cells as high bcl-2. The percentage of cells with a pos itive reaction was assessed independently by two pathologists, and the resu lts were subjected to statistical analysis using Fischer's exact test. Results and conclusion: No statistically significant correlation was found between the expression of bcl-2 oncoprotein and the clinicopathologic featu res analyzed. However, the high percentage of tumors with positive expressi on of this oncoprotein suggests that it plays a significant role in the bio logy of uveal melanoma.