Registry Study in MSI/dMMR Solid Tumors

Inclusion Criteria: * Sign the informed consent form and voluntarily participate in this study; * Age ≥ 18 years old; age should also be ≤75 years old in Cohorts B, C, D; * Histologically or cytologically confirmed to have a solid malignant tumor and confirmed by immunohistochemistry to be dMMR or confirmed by PCR/NGS to be MSI; * The researcher determines that the patient can receive anti-tumor treatment; * Have evaluable lesions Exclusion Criteria: * Other malignant tumors within 5 years before joining the study, except for cured skin squamous cell carcinoma, basal cell carcinoma, non-muscle invasive bladder cancer, localized low-risk prostate cancer (defined as stage ≤T2a, Gleason score ≤6 points, and prostate cancer diagnosed with PSA ≤10 ng/mL (if measured). Patients who have received radical treatment and have no prostate specific antigen (PSA) biochemical recurrence can participate in this study), cervical/breast carcinoma in situ, and Lynch syndrome; * Evidence already exists that the patient is a pregnant or lactating woman; * Previous treatment with immune checkpoint inhibitors or T cell co-stimulatory drugs, including but not limited to PD1, CTLA4, LAG3, and other immune checkpoint blockers, therapeutic vaccines, etc.; patients exposed to ICIs in perioperative setting are allowed to be enrolled if disease relapse after more than 6 months since the last dose of ICIs; * Other situations deemed by the researcher to be unsuitable for inclusion in the study