Colorectal medullary carcinoma: a pathological subtype with intense immune response and potential to benefit from immune checkpoint inhibitors.

INTRODUCTION: Different pathological types of colorectal cancer have distinguished immune landscape, and the efficacy of immunotherapy will be completely different. Colorectal medullary carcinoma, accounting for 2.2-3.2%, is characterized by massive lymphocyte infiltration. However, the attention to the immune characteristics of colorectal medullary carcinoma is insufficient. AREA COVERED: We searched the literature about colorectal medullary carcinoma on PubMed through November 2023to investigate the hallmarks of colorectal medullary carcinoma's immune landscape, compare medullary carcinoma originating from different organs and provide theoretical evidence for precise treatment, including applying immunotherapy and BRAF inhibitors. EXPERT OPINION: Colorectal medullary carcinoma is a pathological subtype with intense immune response, with six immune characteristics and has the potential to benefit from immunotherapy. Mismatch repair deficiency, ARID1A missing and BRAF V600E mutation often occurs. IFN-γ pathway is activated and PD-L1 expression is increased. Abundant lymphocyte infiltration performs tumor killing function. In addition, BRAF mutation plays an important role in the occurrence and development, and we can consider the combination of BRAF inhibitors and immunotherapy in patients with BRAF mutant. The exploration of colorectal medullary carcinoma will arouse researchers' attention to the correlation between pathological subtypes and immune response, and promote the process of precise immunotherapy.

China special issue on gastrointestinal tumors-Regulatory-immunoscore-A novel indicator to guide precision adjuvant chemotherapy in colorectal cancer.

Novel biomarkers are essential to improve the treatment efficacy and overall survival of stage II and III colorectal cancer (CRC), allowing for personalized treatment decisions. Here, the densities of CD8+ and FOXP3+ T cells in the tumor and invasive margin were processed by immunohistochemistry and digital pathology to form a scoring system named regulatory-Immunoscore (RIS). Cox proportional hazards regression models were used to determine the risk factors associated with time to recurrence. Harrell's concordance index and the time-dependent area under the curve were used to assess model performance. A total of 1213 stage I-III DNA mismatch repair-proficient colorectal cancer (pMMR CRC) patients were randomly assigned to a training set (n = 642) and a validation set (n = 571). From the Cox multivariable analysis, the association of RIS with survival was independent of patient age, sex and anatomy-based tumor risk parameters (P < .0001). For stage II patients, chemotherapy was significantly associated with better recurrence time in patients with low (95% confidence interval [CI]: 0.11-0.54, P = .001) and intermediate (95% CI = 0.25-0.57, P < .001) RIS values. In stage III patients treated with adjuvant chemotherapy, a treatment duration of 6 or more months was significantly associated with better recurrence time in patients with intermediate RIS values (95% CI = 0.38-0.90, P = .016) when compared with duration under 6 months. Therefore, these findings suggest that RIS is reliable for predicting recurrence risk and treatment responsiveness for patients with stage I-III pMMR CRC.

Comparative efficacy and toxicity of immune checkpoint inhibitors in combination with or without chemotherapy treatment for advanced esophageal squamous cell carcinoma: A systematic review and meta-analysis.

Introduction: We did a systematic review and meta-analysis to assess the efficacy and safety of immune checkpoint inhibitors combined with or without chemotherapies in patients with esophageal squamous cell carcinoma. Methods: Data related to the treatment of esophageal squamous cell carcinoma with immune checkpoint inhibitors therapy were retrieved from the database construction to August 2022. The risk of bias was assessed using the Cochrane Manual standard and RevMan 5.3 software for data synthesis. The outcome measures observed included overall survival, 12-month survival, disease control rate, objective response rate, treatment-related adverse events of grade 3 or higher, and progression-free survival. The adverse reactions included fatigue, diarrhea, hypothyroidism, rash, anemia, and anorexia. Results: In this meta-analysis, a total of 17 randomized controlled trials were included. In first-line therapy, immune checkpoint inhibitors combined with or without chemotherapy in the treatment of esophageal squamous cell carcinoma was more effective than chemotherapy alone. Overall survival, 12-month survival rate, and objective response rate were statistically significant. Among second-line treatments, immune checkpoint inhibitors combined with or without chemotherapy in the treatment of esophageal squamous cell carcinoma had statistically significant overall survival, 12-month survival, objective response rate, treatment-related adverse events of grade 3 or higher, and progression-free survival compared with chemotherapy alone. Conclusion: Both first- and second-line immune checkpoint inhibitors are effective for esophageal squamous cell carcinoma, and the adverse reactions are controllable and safe. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021282586.