Comprehensive analysis of intratumoral lymphocytes and FOXP3 expression in tumor cells of endometrial cancer

Abstract

Aim: To study the tumor microenvironment (CD4⁺, CD8⁺ and FOXP3⁺ lymphocytes) and FOXP3 expression by tumor cells and correlation of studied parameters with clinical and morphological characteristics of endometrial adenocarcinomas. Materials and Methods: Tumor samples from 40 patients (mean age 56.9 ± 2.8) with endometrial cancer (EC), who did not receive special treatment before surgery (chemotherapy, radiation therapy and hormontherapy), were investigated. Morphological, immunohistochemical methods as well as methods of mathematical statistics were applied in the study. Results: It has been determined that high quantity of FOXP3⁺ tumor cells and intratumoral CD4⁺ and CD8⁺ Т-lymphocytes along with the low content of FOXP3⁺-lymphocytes is typical for the endometrial adenocarcinomas of high differentiation grade (G1). In poorly differentiated (G3) EC an increase of number of FOXP3⁺-lymphocytes and decrease of CD4⁺ and CD8⁺ lymphocytes in lymphocytic infiltrate have been observed. Moreover, decrease of the content of FOXP3⁺ tumor cells has been determined. In EC patients correlation between the following parameters has been detected: proliferative activity and deep invasion of tumor in myometrium (R = 0.74); depth of invasion correlated with the number of the FOXP3⁺ tumor cells (R = −0.63) and number of CD4⁺ and CD8⁺ lymphocytes (R = 0.68 and R = −0.55 respectively) in lymphocytic infiltrate. Thus, results of this study are the evidence of significance of the lymphocytic components of tumor microenvironment and content of FOXP3 expressing tumor cells in EC progression. Conclusion: Quantitative changes of tumor microenvironment, such as number of CD4⁺, CD8⁺ and FOXP3⁺ lymphocytes and content of FOXP3⁺ tumor cells correlate with biological characteristics of EC. Key Words: endometrial cancer, FOXP3⁺ tumor cells, intratumoral FOXP3⁺ lymphocytes, intratumoral CD4⁺, CD8⁺ Т-lymphocytes, depth of invasion, proliferative potential.