Tumour infiltrating lymphocytes in relation to tumour angiogenesis, apoptosis and prognosis in patients with large cell lung carcinoma

Immune escape of tumour infiltrating lymphocytes (TILs), angiogenesis and a poptosis are important factors that contribute to tumour growth. In the pre sent study immunohistochemical methods were used to investigate the relatio nships of these factors and their role in the prognosis of 38 patients oper ated on for a large cell lung carcinoma (LCLC). T cells and macrophages wer e most commonly found TILs in LCLC while the number of intratumoural B cell s was small. A high number of intratumoural macrophages associated with ang iogenesis, as measured by microvessel density (MD). TILs were not associate d with the extent of apoptosis in LCLC, as measured by in situ 3'-end label ling of apoptotic DNA. The high number of intratumoural macrophages and B c ells was a prognostic marker showing a better survival time of the patients with LCLC. Furthermore, a high number of inratumoural macrohages was signi ficantly associated with longer disease free survival and low tumour stage of the patients with LCLC. A high number of intratumoural B cells and macro phages was associated with a small tumour size suggesting that both B cells and macrophages are important TILs limiting the growth of LCLC. Instead, T cells were not associated with survival or with the size or stage of the t umour suggesting that cytotoxic T cells are less important mediators of tum our host interaction in LCLC than B cells and macrophages. (C) 1999 Elsevie r Science Ireland Ltd. All rights reserved.