Evaluation of apoptosis markers in conjunctival and eyelid benign and malignant tumors.

The balance between cell proliferation and programmed cell death plays a crucial role in malignant development. Bcl-2 family proteins, including proapoptosis protein Bak and antiapoptosis protein Bcl-2, regulate the apoptotic process. Mutation of the p53 gene, which results in P53 protein accumulation, was observed in many types of human cancer. The aim of our study was to evaluate immunohistochemical Bcl-2, Bak, and P53 protein expression and the relation between these proteins in conjunctival and eyelid benign and malignant tumors. We examined a series of 42 papillomas (CEP), 12 squamous cell cancers (SCC), and 19 cases of basal cell cancer (BCC). The age in the CEP group ranged from 18-94 years, and in the SCC and BCC groups from 42-87 years. Staining patterns were correlated with sex, age, and tumor localization. P53 protein-positive immunostaining was observed in 71% of cases, Bcl-2 in 83.9%, and Bak in 74.2 cases in the SCC and BCC groups. In the CEP group, P53 overexpression was observed in 90.5% of cases, Bcl-2 in 71.4%, and Bak in 76.2%. No statistically significant correlation was found between examined protein expression and sex, age, and tumor localization. An inverse correlation was observed between P53 and Bak protein expression in the CEP group. No statistically significance correlation was noted between Bcl-2 and P53 and Bcl-2 and Bak protein expression in both examined groups. The obtained data suggests that P53 and Bcl-2 protein expression coupled with decreasing Bak expression are associated with apoptosis and proliferation as well as malignant progression in conjunctival and eyelid tumors.