Non-small cell lung carcinoma: cyclin D1, bcl-2, p53, Ki-67 and HER-2 proteins expression in resected tumors

The aim of this study was to investigate expression of cyclin D1, bcl-2, p53, Ki-67 and HER-2 proteins in 14 cases of non-small cell lung cancer and to establish their correlation to classical clinico-pathological findings, and alleged prognostic value to estimate biological potential of tumor. Retrospective pilot study of the surgically treated non-small cell lung cancer biopsy specimen, paraffin embedded, used immunohistochemical method to demonstrate expression of cyclin D1, bcl-2, p53, Ki-67 and HER-2. Protein quantification was performed by the semi-quantitative method. Achieved results were correlated with classical clinico-pathological parameters, like tumor size, histological type, differentiation level, presence of vascular invasion and metastasis in regional lymph nodes. Out of 14 cases of non-small cell lung cancer, squamous cell carcinoma was found in 7 patients, giant cell carcinoma in 3, adenocarcinoma in 2, and 1 case of pleomorphic and mucoepidermoid carcinoma. Expression of cyclin D1 was not found, while expression of HER-2 and bcl-2 protein was established in one cases each. p53 expression was noted in 8 cases (57,1%). Statistically positive significant correlation (p<0,05) was found among: presence of lymphovascular invasion to tumor tissue and appearance of nodal metastasis; proliferation Ki-67 index and level of tumor differentiation, i.e. size of tumor. Other investigated parameters showed no significant statistically dependence. p53 expression was not correlated to any of the investigated parameters what might imply the possibility that there is an independent pathway of this protein expression. Negative expression of bcl-2 protein points out to possibility that it is not included into process of tumor apoptosis, as well as that proteins cyclin D1 and HER-2 are not included into processes of the tumor genesis. Since the proliferative activity of the tumor, measured by the expression of Ki-67, is correlated to the gradus and size of the tumor mass, Ki-67 protein can be of a prognostic value to determine biological potential of non-small cell lung cancer.