ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 PS-07-005 Tumour infiltrating lymphocytes (TILs) relate to PD-L1 expres- sion and provide prognostic value in stage II and III colon can- cer patients P. Azcue*, I. Encío, R. Vera, M. Mercado, M.L. Gómez-Dorronsoro *Department of Health Science, Public University of Navarra (UPNA), France Background & objectives: Tumour-infiltrating lymphocytes (TILs) and PD-L1 expression have been suggested as markers of immune-response in colon cancer also providing prognostic value. The aim is to assess TILs in the invasive primary tumour front, its relationship with PD-L1 expression and clinical outcomes. Methods: In a cohort of 140 patients with stage II/III colon cancer, TILS were assessed according to the TILs Working Group stand- ardized methodology and underwent automatic immunohistochemi- cal staining for PD-L1. Clinical outcomes assess were disease-free survival and overall survival. The percentage of TILs score was categorized into low (≤ 5%), intermediate (≤ 10%), high (≤ 20%), and highest (> 20%). Results: Assessment of TILs in the intermediate category and above in the tumour sample was statistically significantly related to PD-L1 expression. The higher percentage of TILs found, the stronger association with PD-L1 expression (p<0.001). There was no significant difference between TILs assessment and Stage II or III nor any other baseline characteristic. Category high TILs showed statistical significance for disease free survival HR=0.40 95%CI [0.23-0.95] independent of sex, age, TNM stage and localization. Conclusion: Our results suggest that TILs and PD-L1 expression are closely related. In addition, the presence of TILs in the tumour microenvironment seem to provide a positive prognostic value in early stage colon carcinoma. Immunotherapies that aim to stimulate an immune response may benefit from TILs assessment as a predictor for PD-L1 expression, in addition to its prognostic value. PS-07-006 Novel patterns of V-set and immunoglobulin domain containing 1 expression in gastric cancer C. Satala*, I. Jung, Z. Kovacs, R.I. Stefan-Van Staden, T. Bara, C. Molnar, A. Patrichi, S. Gurzu *University of Medicine, Pharmacy, Science and Technology G. E. Palade, Targu Mures, Romania Background & objectives: V-set and immunoglobulin domain containing 1 (VSIG1) is an intercellular-adhesion molecule expressed in the membrane of the normal gastric mucosa. The aim of this study is to report the possible significance of VSIG1 cytoplasmic translocation in gastric cancer. Methods: Based on VSIG1 immunohistochemical (IHC) expression in tumour core and front in 94 cases, three patterns were established: homologous type I (membrane/membrane), homologous type II (null/null) and heterologous cases (membrane/ cytoplasm or cytoplasm/null). VSIG1 status was correlated with clinico-pathological features (TNM stage and Dukes-MAC-like stage, molecular phenotype) and survival rate. Results: From the 94 cases, 21.27% showed homologous type I expression, with the same percentage for cases with heterologous patterns. The rest of 57.46% demonstrated homologous type II pat- tern. Heterologous patterns were indicators of aggressive behav- iour, such as advanced Dukes-MAC-like stage (p=0.02), lymph node metastases (p=0.03) and mesenchymal tumour phenotype, with loss of E-cadherin expression (p=0.004) and nuclear trans- location of β-catenin (p=0.0007). Cytoplasmic expression was more frequently seen in poorly differentiated/undifferentiated carcinomas. In cases with heterologous pattern, overall survival was significantly poorer, compared to that of cases with homolo- gous expression (p=0.0005). Conclusion: In gastric carcinomas, VSIG1 cytoplasmic positivity might be an indicator of mesenchymal phenotype, and thereby, a marker for dismal prognosis, aggressive behaviour and shorter overall survival. Funding: This work was supported by the Romanian National Authority for Scientific Research, Project no. 20-PCCF/2018 PS-07-007 Serum and mucosal CD30 in paediatric inflammatory bowel diseases (IBD): useful biomarkers for diagnosis and disease activity monitoring? O. Fabian*, A. Klocperk, T. Lerchova, P. Jencova, L. Stolova, M. Belhajova, D. Voriskova, D. Kazeka, A. Vicha, O. Hradsky, J. Bronsky *Clinical and Transplant Pathology Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic Background & objectives: The underlying immune pathophysiol- ogy of IBD is incompletely understood, rendering quick diagnosis followed by tailored therapy difficult. The TNF superfamily recep- tor CD30 has been proposed as potential marker of ulcerative coli- tis (UC), and has been associated with elevated Th2 cells. Methods: In this study we evaluate a cohort of 94 paediatric patients with UC and Crohn’s disease (CD) for serum soluble CD30 (sCD30) using ELISA, and expression of CD30 and subpopulations of Th1/Th2/Th17 lymphocytes in the gastrointestinal mucosa using flow cytometry (FCM). The dataset is supported by endoscopic and microscopic activity of disease and basic laboratory markers of inflammation. Results: sCD30 was not associated with diagnosis of CD or UC. However, sCD30 levels correlated with levels of CRP, ESR, faecal calprotectin and albumin and also with clinical activity of the disease in both UC and CD patients. FCM was not helpful in evaluation of mucosal CD30, which was lowly expressed and not associated with diagnosis or disease activity. We show augmented Th2 and Th1/17 response in the terminal ileum and right-sided colon and decreased Th1/17 response in left-sided colon of UC patients. T lymphocyte subsets were also affected by anti-TNF treatment and patients’ age. Conclusion: Neither sCD30 nor FCM evaluated mucosal CD30 were helpful in the diagnosis of paediatric UC. sCD30 seems to be marker of systemic inflammation and clinical activity of the disease. Funding: This work was supported by the Grant Agency of Charles University in Prague project no. 728218, and the grant project NU 20-05-00282 issued by the Czech Health Research Council and Ministry of Health, Czech Republic. PS-07-008 Assessment of immune T cells expression in colorectal cancer N. Boujelbene, I. Zemni, S. Dhouioui*, H. Ben Yahia, W. Babay, A. Ben Mansour, K. Mrad, H. Ouzari, I. Zidi *Laboratory Microorganismes and Active Biomolecules, Sciences Faculty of Tunis, Tunisia Background & objectives: Colorectal cancer(CRC) is the second most deadly cancer worldwide. CRC recurrence is at the origin of this high mortality.Resistance to chemotherapy remains one of the greatest challenges causing recurrence. Our study specifically addressed the expression of immune Tcells in CRC. S92