Potential role of tumor-infiltrating T-, B-lymphocytes, tumor-associated macrophages and IgA-secreting plasma cells in long-term survival in the rectal adenocarcinoma patients

Abstract

AimsMany studies investigated the associations between the role of immune cells of rectal cancer microenvironment and survival during the first 5 years post-surgery. This is problematic as this disease has the potential to progress even after 5 years after relapse and infiltrating immune cells could play key roles. Therefore, this retrospective study investigates expression and roles of tumor-infiltrating T-lymphocytes (TIL-T), tumor-infiltrating B-lymphocytes (TILB), IgA+ plasma cells (IgA+ PC) and tumor-associated macrophages (TAM) in patients with or without progression over 5 years survival with rectal adenocarcinoma. Main methodsHere we used immunohistochemical staining of CD3, CD20, IgA, CD68 positive cells and its detection in rectal cancer stroma. Data was analyzed using Mann Whitney U test, ROC, survival and Cox's regression analysis. Key findingsThe number of TIL-T (p = 0.0276), TIL-B (p < 0.0001) and IgA+ PC (p = 0.015) immune cells was significantly higher in rectal cancer stroma of patients with favorable outcome. Univariate Cox's regression analysis revealed a predictive role of TIL-T (HR = 0.482; 95% CI, 0.303 to 0.704; p < 0.0001), TIL-B (HR = 0.301; 95% CI, 0.198 to 0.481; p < 0.0001) and IgA+-PC (HR = 0.488; 95% CI, 0.322 to 0.741; p < 0.0001). Multivariate Cox's regression analysis showed prognostic role of TIL-B (HR = 0.940; 95% CI, 0.914 to 0.968; p < 0.0001) and IgA+-PC (HR = 0.985; 95% CI, 0.975 to 0.996; p = 0.006) play role in long time survival. SignificanceCD20+ TIL-B and IgA+ cells have significant associations with long -term survival of patients with rectal cancer, with potential therapeutic intervention in cancer immunotherapy.