Tumor immune microenvironment and response of immunotherapy in patients with colorectal cancer

Aim: Biomarkers, such as PD-L1, have enabled significant progress in predicting the efficacy of immunosuppressants. However, they may not accurately predict the benefit degree from immunotherapy. Therefore, we associated PD-L1 with tumor-infiltrating lymphocytes for accurate guidance in immunotherapy. Methods: The expressions of diverse proteins in 68 patients with positive PD-L1 expression were detected. The response to immunotherapy and its clinical results were observed and analyzed. Results: The overall response rate of immunotherapy differed significantly among groups (75%; 57.58%; 10%; and 0), as did the 3-year overall survival rates (72.73%, 54.84%, 11.11%, and 0). Conclusion: We identified four immune subtypes of colorectal cancer with different tumor-infiltrating lymphocytes (TILs), and constructed a highly operable method for immunotyping to predict the immunotherapy efficacy. TWEETABLE ABSTRACT We identified four immune subtypes of colorectal cancer with different TILs, their distribution, and different immune responses and constructed a highly operable and simple method for immunotyping.