Long-term complete remission achieved by pembrolizumab for dMMR/MSI-H advanced colon cancer:a case report
ZHANG Sheng-hui
WANG Di
CHENG Shuai-hua
LIN Yang
LI Hong-ling
Abstract：Colorectal cancer(CRC)is the third most common malignancy and the second leading cause of cancer-related deaths worldwide and has become a major threat to global health.In recent years,various screening and detection technologies have emerged;however,approximately 25％of CRC patients are still diagnosed at an advanced stage.Up to 50％of patients with initially localized disease develop metastases,and the 5-year survival rate for metastatic CRC remains below 15％.Furthermore,traditional treatments exhibit significant variability in response to molecularly heterogeneous tumors.Breakthroughs in immune checkpoint inhibitors(ICIs)have provided new treatment modalities for advanced CRC,particularly for patients with the microsatellite instability-high(MSI-H)/mismatch repair deficiency(dMMR)subtype.This report details the case of a 55-year-old man with dMMR/MSI-H advanced colorectal cancer(CRC).Following multiple prior treatment failures,the initiation of pembrolizumab led to rapid tumor shrinkage and a sustained decline in tumor markers.The patient attained complete remission(CR)after seven treatment cycles and achieved long-term survival,with a follow-up of five years.This case study explored the decision-making process in cancer diagnosis and treatment,thereby providing a valuable reference for clinical practice.
Keywords：advanced colorectal cancerdMMR/MSI-Hpembrolizumabimmunotherapylynch syndrome
Publication Date：2026-05-30
Online Publishing Date：2026-08-14(First online date of this platform, not the publication date of the document)
Pages：5( 1108-1112 )