Background: Apoptosis is regulated by many genes, including bcl-2, p53, and bcl-2 family genes. The expression of Bcl-2, p53, and Bax in very early lung cancers or precancer lesions is not been fully understood.
Materials and methods: The expression of these proteins was examined immunohistochemically in 11 normal bronchial epithelia, 23 dysplasias, and 40 roentgenographically occult squamous cell lung cancers (ROCs).
Results: The expression of the Bcl-2 and p53 protein increased along with the advance of the morphological atypia in bronchial epithelial cells, whereas no difference in the Bax expression. The patients with Bcl-2 positive ROCs had a better prognosis than those with Bcl-2 negative ROCs.
Conclusions: Bcl-2 and p53 proteins play important roles in early steps of carcinogenesis in squamous cell lung cancer of central type. The Bcl-2 protein could be a prognostic marker in ROCs.