Case Report
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Dec 15, 2023; 15(12): 2237-2241
Published online Dec 15, 2023. doi: 10.4251/wjgo.v15.i12.2237
Conversion immunotherapy for deficient mismatch repair locally unresectable colon cancer: A case report
Zhen Sun, He Liu, Guan-Nan Zhang, Yi Xiao
Zhen Sun, Guan-Nan Zhang, Yi Xiao, Division of Colorectal Surgery, Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
He Liu, Department of Gastrointestinal Surgery, The People's Hospital of Huangdao District, Qingdao 266400, Shandong Province, China
Author contributions: Sun Z and Liu H collected data and drafted the manuscript; Zhang GN participated in data acquisition and interpretation; Xiao Y revised and finalized the manuscript; all authors have read and approved the final manuscript.
Supported by National High Level Hospital Clinical Research Funding, No. 2022-PUMCH-C-027.
Informed consent statement: Written informed consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: Written informed consent was obtained from the patient for publication of this report and any accompanying images.
CARE Checklist (2016) statement: The authors read the CARE Checklist (2016) and the manuscript was prepared and revised according to this checklist.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Yi Xiao, PhD, Chief Doctor, Division of Colorectal Surgery, Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Shuai Fu Yuan, Dongcheng District, Beijing 100730, China. xiaoy@pumch.cn
Received: October 26, 2023
Peer-review started: October 26, 2023
First decision: October 30, 2023
Revised: October 31, 2023
Accepted: November 5, 2023
Article in press: November 5, 2023
Published online: December 15, 2023
Processing time: 48 Days and 20.3 Hours
Abstract
BACKGROUND

Owing to the special features of biologics, deficient mismatch repair (dMMR) in patients with colon cancer has achieved little treatment efficacy from chemoradiotherapy. Immunotherapy has shown promising results for the treatment of colon cancer. The high response rate observed suggests a great option for patients presenting with unresectable tumors, as it allows for better oncological resection. Here, we aimed to highlight the significant effects of immunotherapy on dMMR in colon cancer.

CASE SUMMARY

A 54-year-old man diagnosed with locally unresectable dMMR colon cancer received preoperative immunotherapy (three cycles of pembrolizumab) and achieved a pathological complete response after surgery.

CONCLUSION

Immunotherapy can be used as a conversion treatment for locally unresectable colon cancer with dMMR.

Keywords: Colon cancer; Immunotherapy; Pathological complete response; Case report

Core Tip: Surgery remains the primary radical therapy for colon cancer and resection radicality is one of the most important predictors for survival. Preoperative chemotherapy has been proven to ameliorate resection radicality and survival. Due to the special features of biologics, deficient mismatch repair (dMMR) colon cancer patients achieved little treatment efficacy from chemoradiotherapy. Up to now, immunotherapy has shown promising responses in colon cancer. We aim to draw attention to the significant effect of immunotherapy on dMMR colon cancer.