Abstract
Non-small cell lung carcinomas (NSCLC) are the most common histological forms of lung cancer, lesions that by their incidence and associated mortality constitute a health problem worldwide. Alteration of the expression of claudins with a role in the stability of cell adhesion constitutes one of the complex biomolecular mechanisms involved in tumor initiation and progression. In this study, Claudin-4 immunoexpression was investigated in 52 cases of NSCLC in relation to epidemiological and histopathological prognostic parameters of the lesions. Although the staining scores were higher in patients in younger age groups, in women, in smokers and in squamous cell carcinomas (SCC) and large cell carcinoma (LLC) compared to adenocarcinomas (ADK), the aspects were not statistically significant. We found significantly higher differences in micropapillary, cribriform and solid ADK compared to other histological subtypes, in well and poorly differentiated lesions (G1/G3), with vascular invasion and in advanced tumor stages. Reaction analysis indicated translocation of Claudin-4 signals from the membrane level to the cytoplasm and nucleus in aggressive histological subtypes. The study indicated differences in Claudin-4 expression, which can be used to identify aggressive NSCLC and to stratify patients for specific therapy.