The Efficacy of Watch and Wait Strategy or Surgery After Neoadjuvant Immunotherapy for Locally Advanced Colorectal Cancer With dMMR/MSI-H Guided by MRD Dynamic Monitoring(WINDOW): A Single-center, Open-label, Prospective, Phase II Clinical Trial.
This study is a single arm, single center, phase II, prospective clinical study aimed at exploring the effectiveness and safety of watch and wait strategy guided by dynamic minimal disease residual (MRD) monitoring to achieve clinical complete response after neoadjuvant immunotherapy for locally advanced colorectal cancer with deficient mismatch repair/ microsatellite instability-high (dMMR/MSI-H).
• ( 1 ) Disease characteristics 1. Histologic confirmation for colorectal adenocarcinoma; 2．Immunohistochemical identified as dMMR and/or pCR and/or NGS detection for MSI-H; 3．According to UICC/AJCC TNM staging system (in 2017 version 8) assessment for locally advanced colorectal cancer (II - III, namely cT3-4 and/or N + ）； 4.\* clinical staging methods: colon CT staging, approved by pelvic magnetic resonance imaging (MRI) and the rectum rectum cavity ultrasound combined with staging, 5．No signs of intestinal obstruction;Or intestinal obstruction after proximal colon obstruction has been relieved after colostomy surgery; 6．No distant metastasis was confirmed by comprehensive examination (distant organs or (and) the distant lymph node metastasis); ( 2 ) Previous treatment 1．No colorectal cancer surgery before; 2. No previous chemotherapy or radiotherapy ; 3. had not received biological treatment ; 4. Previous endocrine therapy : no restriction.