[Tumor escaping mechanisms present in microenvironment of laryngeal cancer]

In tumor tissue obtained from a group of 21 patients treated surgically for laryngeal carcinoma, the expression of Fas, Fas-L, CD3, TCR zeta chain and Bcl-2 were estimated. It has been shown that tumor often express: Fas-L, Fas, Bcl-2, the molecules which may influence increased tumor survival. On the other hand lack of MHC class I antigen expression on tumor cells frequently has been observed. As it is known, such tumor cells can not be recognized by cytotoxic T lymphocytes. Frequently observed decreased expression of TCR zeta chain and high level of apoptosis among T cells present in tumor microenvironment seems to depend on direct interactions with molecules expressed by tumor. Understanding of these interactions may be of great importance in evaluation of tumor aggressiveness, patients follow up and the approach to treatment.