Abstract 3748: Evaluation of immune cells from patient-derived tumor tissue and peritoneal washing cytology in correlation with immunohistochemical markers in endometrial cancer

Abstract

Abstract Background This study aims to evaluate the characteristics and clinical correlations of tumor-infiltrating lymphocytes (TILs) in endometrial cancer, derived from fresh tumor tissue and peritoneal washing cytology. Furthermore, it seeks to explore the correlation between TILs and immunohistochemical markers in endometrial cancer. Methods In this study, we investigated the nature of TILs extracted from endometrial tissue and peritoneal washing cytology, along with their correlation with immunohistochemical markers. Samples collected from endometrial cancer patients during surgery, with informed consent, were analyzed for immune cell composition using flow cytometry. We examined the association between pathological findings, a range of immunohistochemical markers (including LVSI, PD-L1, ER, P53, HER2, MLH1, MSH2, MSH6, PMS2, MSI), and the status of tumor-infiltrating immune cells (such as CD3-CD19+ B Cells, CD3-CD16+CD56+ NK Cells, CD4+CD25+ regulatory T cells (Treg), and CD3+CD8+ cytotoxic T cells). Results Our analysis encompassed 25 endometrial cancer-derived samples. Notable observations include an increase in CD3-CD19+ B cells in the LVSI-positive group and a decrease in the ER-positive group (p<0.05, respectively). CD3-CD16+CD56+ NK Cells decreased in the ER-positive group, while CD3+CD8+ cytotoxic T cells were decreased in the HER2-positive group (p<0.001, p<0.05, respectively). Other immunohistochemical markers showed no significant differences. Conclusion The study suggests that tumor-infiltrating immune cells from patient-derived tissue and peritoneal washing cytology may reflect the molecular and clinical characteristics of endometrial cancer. However, further research with an expanded sample size and correlation with oncologic outcomes is warranted to validate these findings. Citation Format: Changmin Shin, Seungmee Lee, Hyewon Chung, Jin Young Kim, Eunyoung Ha, Ji Hae Seo, Sojin Shin. Evaluation of immune cells from patient-derived tumor tissue and peritoneal washing cytology in correlation with immunohistochemical markers in endometrial cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3748.