2. Histologically or cytologically confirmed, or clinically diagnosed based on currently accepted standards, NET tumors metastatic to the liver that are not amenable at the time of enrolment to resection, transplant or other potentially curative therapy. Patients must have at least one common NET symptom (European Organization for Research and Treatment of Cancer GI.NET21 instrument score of 2 or more at baseline) including: flushing, diaphoresis, diarrhea, abdominal discomfort, hyperacidity, dyspnea or palpitations.