Deficient mismatch repair/microsatellite instability-high (dMMR/MSI-H) metastatic colorectal cancer (CRC) is highly sensitive to immune checkpoint inhibitors due to the high tumor mutation load and neoantigen enrichment. However, 45%-60% of patients exhibit primary or acquired immunotherapy resistance. The mechanisms underlying this resistance are complex, involving tumor microenvironment heterogeneity, co-expression of multiple immune checkpoints, aberrant activation of oncogenic pathways, metabolic dysregulation, intestinal microbiota imbalance, HLA-Ⅰ molecule defects, and epigenetic regulation. Current strategies aimed at reversing immunotherapy resistance include combination immunotherapies, personalized neoantigen vaccines, intestinal microbiota transplantation, epigenetic interventions, and adoptive immune cell therapies. Further analysis of the potential mechanisms of immune therapy resistance in dMMR/MSI-H metastatic CRC, and the exploration of current strategies to overcome resistance can provide a theoretical basis for reversing the immunotherapy resistance in such patients.

Objective To discuss the CT features and pathologic basis of hepatic alveolar echinococcosis. Methods Total 19 cases were confirmed by ELISA and IHA of antibody of echinococcosis. A part of them were confirmed by pathalogy. Results The main features of the disease were irregular,obscure contour and heterogeneous density with mainly hypodense in the liver. Almost of all accompanied with calcification. The calcification was showed some certainly signification. No contrast enhancement was observed within the lesions after administration of intravenous contrast medium. There were three type of this disease based on CT features including map type, halo type and pseudocystic type. Conclusion CT scanning has value of not only for diagnosis of hepatic alveolar echinococcosis but also useful to display each complications and metastasis.