Liver Transplantation Versus Conventional Medical Therapy for Low-Grade GEP-NET With Liver Metastases

Inclusion Criteria: 1. Age 18-70 years at enrollment. 2. Histologically confirmed, well-differentiated (G1 or G2) gastroenteropancreatic neuroendocrine tumor (pancreatic or midgut/hindgut primary). 3. Unresectable, liver-dominant metastatic disease (multifocal/bilobar involvement not amenable to curative resection or ablation). 4. Ki-67 proliferation index ≤ 10% at the most recent biopsy, with stable disease for at least 6 months on standard therapy. 5. Primary tumor resected, or resectable/planned for resection as part of the treatment strategy. 6. No uncontrolled extrahepatic metastatic disease. 7. ECOG performance status 0-1. 8. Treatment group assigned by patient/family preference after balanced multidisciplinary counseling; both options (transplantation vs conventional therapy) medically feasible and discussed. 9. Written informed consent. Exclusion Criteria: 1. Poorly differentiated neuroendocrine carcinoma (G3, Ki-67 above threshold) or mixed neuroendocrine/non-neuroendocrine neoplasm (MiNEN). 2. Uncontrolled extrahepatic metastases or progressive disease despite adequate systemic therapy at enrollment. 3. For candidates considering transplantation: serious comorbidities precluding major surgery, including uncontrolled cardiopulmonary disease, active infection, decompensated cirrhosis with severe portal hypertension, or other contraindications to transplantation and immunosuppression. 4. Pregnancy or lactation. 5. Other active malignancy within the past 5 years (except adequately treated non-melanoma skin cancer or cervical carcinoma in situ). 6. Inability or unwillingness to comply with protocol follow-up. 7. Participation in another interventional clinical trial with potential interference with endpoints.