Neoadjuvant immunotherapy for dMMR/MSI-H locally advanced rectal cancer: The future new standard approach?

Introduction: This is a review of the evidence from studies of the efficacy and tolerability of neoadjuvant immunotherapy for mismatch repair-deficient (dMMR) or microsatellite instability-high (MSI-H) Locally Advanced Rectal Cancer (LARC). Methods: For this review, we searched EMBASE and MEDLINE until 22 September 2022. The terms used in the search included mismatch repair-deficient, microsatellite instability, rectal cancer, neoadjuvant and immunotherapy. Results: A total of 92 studies were obtained but only 9 were selected for the final analysis (one pro-spective and eight retrospective studies), including less than 20 patients per study. Neoadjuvant immunotherapy provides overall response rates of 100% (with and completed clinical response between 40 and 100%). Conclusion: Our review discusses completed prospective and retrospective studies, ongoing clinical trials, and the clinical practice of using neoadjuvant immunotherapy for MSI-H/dMMR LARC. The promising results obtained, would open the door to exploring other alternatives for these patients, of-fering the possibility of avoiding chemoradiation therapy and surgery in the future. (c) 2022 Elsevier Ltd, BASO -The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

Automated summary

This review summarizes the evidence from studies on the efficacy and tolerability of neoadjuvant immunotherapy for mismatch repair-deficient (dMMR) or microsatellite instability-high (MSI-H) Locally Advanced Rectal Cancer (LARC). A total of 92 studies were obtained, but only 9 were included in the final analysis, showing overall response rates of 100%. The promising results suggest the potential to explore alternative treatments for these patients in the future.