Organ preservation in locally advanced colorectal cancer with microsatellite instability-high after immunotherapy

• Published in: Zhonghua wei chang wai ke za zhi Vol. 27; no. 4; p. 353
• Main Authors: Hong, Z G, Xiao, B Y, Ding, P R
• Format: Journal Article
• Language: Chinese
• Published: China 25.04.2024
• ISSN: 1671-0274
• DOI: 10.3760/cma.j.cn441530-20240223-00070

Neoadjuvant immunotherapy has achieved exciting efficacy with high clinical complete response (cCR) and pathologic complete response (pCR) rates and durable long-term effects. PD-1 checkpoint blockade-based immunotherapy has been highly successful in microsatellite instability high (MSI-H)/mismatch repair deficiency (dMMR) colorectal cancer and has been recommended as the first-line treatment for metastatic colorectal cancer by domestic and international guidelines. Several studies have shown that immunotherapy can be a potentially curable treatment for MSI-H rectal cancer and has even shown promise in organ preservation in colon cancer. In this study, we first clarified the feasibility of the watch-and-wait strategy after PD-1 checkpoint blockade treatment by indirect and direct evidence. Then from the assessment tools (including digital rectal examination, endoscopy, radiology, and lymph node assessment), the viable assessment methods of cCR for immunotherapy and related difficulties are proposed. Finally,