Study of Lanreotide in Patients With Metastatic Gastrointestinal Neuroendocrine Tumors Who Are Undergoing Liver-directed Radioembolization With Yttrium-90 Microspheres

Inclusion Criteria: * Metastatic well-to-moderately differentiated (or low-grade) neuroendocrine carcinoma, including typical carcinoid or pancreatic islet cell carcinoma. * Computerized tomography (CT) scan evidence of liver metastases which are not treatable by surgical resection or local ablation with curative intent at the time of study entry. If a CT scan is not possible, then an MRI may be used. * Patients who are currently receiving or have previously received lanreotide or another somatostatin analogue are eligible. Previous treatment with lanreotide or another somatostatin analogue is not required for study entry. * Eastern Cooperative Oncology Group (ECOG) Performance Status score of 0 or 1. * Adequate hematologic, hepatic and renal function. * Male patients with female partners of childbearing potential and women patients of childbearing potential are required to use two forms of acceptable contraception, including one barrier method, during their participation in the study and for 3 months (90 days) following last dose of study drug(s). Male patients must also refrain from donating sperm during their participation in the study and for 3 months after last dose of study drug(s). * Life expectancy ≥ 3 months. * Willingness and ability to comply with study and follow-up procedures. * Ability to understand the nature of this study and give written informed consent. Exclusion Criteria: * Anti-cancer therapy with the exception of lanreotide or another somatostatin analogue within 21 days or 5 half-lives (whichever is shorter) of starting study treatment. * Wide field radiotherapy (including therapeutic radioisotopes such as strontium 89) administered ≤28 days or limited field radiation for palliation ≤7 days prior to Cycle 1 Day 1 or has not recovered from side effects of such therapy. * Major surgical procedures ≤28 days of beginning study drug, or minor surgical procedures ≤7 days. No waiting required following port-a-cath placement. * Previously untreated brain metastases. Patients who have received radiation or surgery for brain metastases are eligible if therapy was completed at least 2 weeks prior to study entry and there is no evidence of central nervous system disease progression, mild neurologic symptoms, and no requirement for chronic corticosteroid therapy. * Clinically significant ascites, cirrhosis, portal hypertension, or thrombosis as determined by clinical or radiologic assessment. * Pregnant or lactating. * Acute or chronic liver, renal, or pancreas disease. * Any of the following cardiac diseases currently or within the last 6 months: * Left Ventricular Ejection Fraction (LVEF) \<45% as determined by Multiple Gated Acquisition (MUGA) scan or echocardiogram (ECHO) * QTc interval \>480 ms on screening electrocardiogram (ECG) * Unstable angina pectoris * Congestive heart failure (New York Heart Association (NYHA) ≥ Grade 2 * Acute myocardial infarction * Conduction abnormality not controlled with pacemaker or medication * Significant ventricular or supraventricular arrhythmias (patients with chronic rate-controlled atrial fibrillation in the absence of other cardiac abnormalities are eligible) * Valvular disease with significant compromise in cardiac function * Inadequately controlled hypertension (i.e., systolic blood pressure \[SBP\] greater than 180 mmHg or diastolic blood pressure (DBP) greater than100 mmHg) (patients with values above these levels must have their blood pressure (BP) controlled with medication prior to starting treatment). * Currently receiving treatment with therapeutic doses of warfarin sodium. Low molecular weight heparin is allowed. * Serious active infection at the time of treatment, or another serious underlying medical condition that would impair the ability of the patient to receive protocol treatment. * Known diagnosis of human immunodeficiency virus, hepatitis B or hepatitis C. Lab test results will be confirmed by the treating physician prior to study enrollment using patient's records not more than 1 year old. * Presence of other active cancers, or history of treatment for invasive cancer ≤5 years. Patients with Stage I cancer who have received definitive local treatment and are considered unlikely to recur are eligible. All patients with previously treated in situ carcinoma (i.e., non-invasive) are eligible, as are patients with history of non-melanoma skin cancer. * Psychological, familial, sociological, or geographical conditions that do not permit compliance with the protocol.