Variable prognostic value of stromal tumor-infiltrating lymphocytes and CD3+T cells in schistosomal and non-schistosomal colorectal cancer

Abstract

Abstract Aim: To investigate the prognostic value of the TILs and CD3+ cells and CD20+ cells in schistosomal colorectal cancer (SCRC) and non-schistosomal CRC (NSCRC).Background: Although schistosomiasis has been basically eliminated, it has not been completely extinction in China and occasional outbreaks occur in Europe recently. The relationship between schistosomiasis and CRC is still obscure, and the inflammation based prognostic systems of schistosomal colorectal (SCRC) and Non-schistosomal CRC (NSCRC) has rarely been reported.Methods: HE-stained sections of 351 CRC tumors, which were completely resected, were evaluated for density of TILs. Meanwhile, we evaluated CD3+T lymphocytes and CD20+B lymphocytes by immunochemistry. The relationship of these infiltrating immune cells with clinicopathological features, including schistosomiasis, and clinical outcomes were evaluated and the prognostic roles of TILs in SCRC and NSCRC were explored.Results: Tumour-infiltrating lymphocytes were negatively correlated with tumor size，pathological T stage, lymph node metastasis and number of tumor budding (p＜0.05). CD3 was also inversely associated with tmuor size, tumor budding, pathological T stage (p＜0.05). And CD20 was correlated with colonic perforin (p=0.003). Besides, sTILs were correlated with the density of iTILs，CD3 and CD20 cells (p＜0.05), CD3 and CD20 were correlated with each other (p＜0.05). In the whole cohort, multivariate analysis identified sTILs and CD3 as independent prognostic factors (p < 0.05), but not the CD20. In subgroups，merely CD3 (p=0.012) was independent prognostic factors both in the NSCRC and SCRC set (p < 0.05). Conclusion: The prognostic roles of sTILs, and CD3+ T and CD20+ B cells were different in CRC patients with and without schistosomiasis, suggesting distinguished role in the immune microenvironment in SCRC and NSCRC patients.