AUTHOR=Zhang Jinli , Yang Lu , Kong Fanwei , Wu Di , Hu Baoru , Yang Jie , He Jiaxin , Liu Lei 

TITLE=Case report: A combined immunotherapy strategy as a promising therapy for MSI-H colorectal carcinomas with multiple HPD risk factors

JOURNAL=Frontiers in Medicine

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2023.1051034

DOI=10.3389/fmed.2023.1051034

ISSN=2296-858X

ABSTRACT=Approximately 5% of advanced colorectal carcinomas (CRC) are microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) tumors. Nowadays, PD-L1 inhibitors or combined CALT4 inhibitors are the major strategies for advanced or metastatic MSI-H colorectal cancer, but some people still show drug resistance or progression. Combined Immune therapy has been shown to expand the benefit population in non-small-cell lung carcinoma (NSCLC), hepatocellular carcinoma (HCC) and other tumors while reducing the incidence of HPD. Nevertheless, CRC with MSI-H remains rare.Here, we describe an elder patient with MSI-H CRC, carrying MDM4 amplification and DNMT3A co-mutation who responded to Sintilimab plus Bevacizumab and chemotherapy as the first-line treatment without obvious immune-related toxicity. Our case provides a new treatment option for MSI-H CRC with multiple risk factors of HPD and highlights the importance of predictive biomarkers in personalized immunotherapy.