Abstract 3793: Immune cells in gastric cancer

Introduction: Role of TIL and interaction with H. pylori infection is not understood in Gastric Cancer. Methods: Gastric tissue samples were retrospectively collected from 50 patients who were refereed to surgery at Instituto Nacional de Enfermedades Neoplasicas between 2011 and 2012. We prospectively evaluated the distribution and density of tumor-infiltrating lymphocytes (TIL) as well as the presence of H. pylori. An evaluation of the role of the density of different subpopulations of infiltrating immune cells in tissue TMA was additionally performed. Clinicopathological data were collected from medical and pathology reports. Kaplan-Meier estimation curves overall survival (OS) was applied. A p-value ≤0.05 was considered statistically significant. Results: Median age was 52 years and 50% were male, most were HG-3 (83%), Lauren classification (76%) and clinical stage III (50%). Most cases went to subtotal gastrectomy (64%). H. pylori was present in 34% (17/49) and most frequent density was moderate (++) (10/49). Intratumoral TIL mild (92%) and bandlike infiltration (68%). Median percentage of intratumoral CD3, CD4, CD8, CD20, CD68 and CD163 TILs in 5 HPF were 12.00±0.108, 1.55±0.017, 7.96±0.093, 1.34±0.057, 12.30±.054 and 8.88±0.069, respectively. No significant association between immune cell subpopulation density and features was found, however it was a trend to association for: Older age and CD163 (p=0.184), male sex and CD8 (p=0.166) and CD4 (p=0.171), poorly differentiated HG and CD4 (p=0.071), early stage and CD4 (p=0.084), diffuse Lauren classification and CD4 (p=0.13), and H. pylori 0&+/+++ and CD68 (p=0.171). The median follow-up was 4.7 years (CI95%: 4.5-5.0), median survival was 1.7 years (CI95%. 0.6-2.9). Earlier clinical stage (p=0.003), non-lymphatic vascular invasion (p=0.024) and absence of node involvement (p=0.018), early Bormann classification (p=0.030) and absence of metastasis (p=0.029) were associates to survival. In relation to the types of TILs, CD3 ( 6.2, p=0.049), and CD4/CD8 ( 60yr HR: 5.1) Bormann (IV, HR: 22.8), NLR ( 3.86, HR: 19.8) and CD4/CD8 ( Keywords: Gastric cancer, tumor-infiltrating lymphocytes, H. pylori This study was supported by the CIENCIACTIVA-CONCYTEC, under the contract #197-2015-FONDECYT Citation Format: Carlos Castaneda, Miluska Castillo, Luis Bernabe Monsalve, Joselyn Sanchez Sifuentes, Eduardo Payet Meza, Eloy Ruiz, Fernando Barreda Bolanos, Manuel Chumpitaz La Rosa Sanchez, Brayam Felix, Katherine Tello, Claudio Flores, Carlos Chavez, Ivan Chavez Passiuri. Immune cells in gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3793.