Oxaliplatin-Based Adjuvant Therapy for Gastrointestinal Neuroendocrine Carcinoma**

• Histopathologically-confirmed diagnosis of gastrointestinal neuroendocrine carcinoma
• Patients with radical resection of tumour, unresectable locally-advanced disease or metastatic disease, regardless of tumour stage;
• No restriction on gender, aged between 18 and 75 years old;
• Eastern Cooperative Oncology Group (ECOG) performance status score ≤ 1. Hematological, hepatic and renal function parameters meet the criteria for chemotherapy administration;
• Expected survival time ≥ 3 months;
• Agree to undergo examinations, treatment and follow-up in accordance with this study protocol; agree to provide clinicopathological and follow-up data required for the study; and consent to the use of study-related data for subsequent research;
• Voluntarily participate in this clinical trial, understand the study procedures and be capable of signing the informed consent form.

Exclusion Criteria:

• Presence of another concurrent malignant tumour within 5 years prior to enrolment;
• Received any anti-tumour therapy within six months before enrolment;
• In the investigator's judgment, the patient has concomitant diseases (such as uncontrolled hypertension, severe diabetes, thyroid disorders, psychiatric diseases, etc.) or any other conditions that would seriously endanger patient safety or prevent completion of this study.