Apoptosis is an integral process of the immune system development and existence. Due to the ability of lymphocytes to follow the apoptotic pathway a very negative effect – the escape of tumor cells population from the immune system control is observed. Multiplying malignant cells during the tumor progression cause the synergic effect of tumor cells apoptosis blocation and unfavourable T-lymphocytes apoptosis induction. The lymphocyte cells apoptosis can be induced by the tumor produced substances as well as the receptor spectrum exprimated by the tumor cells. Physical and chemical anti-cancer therapy causing the non-selective apoptosis induction also contributes substantially to the immune system weakening. Fas-receptor (FasR) is constituotionaly expressed on the activated T-lymphocyte surface. The common sign of the lung, colorectal, breast and other carcinomas is the presence of the surfacial Fas-ligand (FasL). During the infiltration process of tumor by the lymphocytes the FasR/FasL interaction is present, which is probably the most effective trigger mechanism of the T cells apoptosis. The contact of T-lymphocytes and tumor cells for the active antitumor immunity is inevitable. The apoptotic pathways modulation of T-lymphocytes provides a space for FasR/FasL induction influence and thus the anticancer immunity efficiency determination.

        Key words: apoptosis, T-lymphocyte, FasR/FasL, carcinoma