Pazopanib Hydrochloride in Treating Patients With Advanced Neuroendocrine Cancer

Inclusion Criteria: * Patients must have histologically or cytologically confirmed low or intermediate grade carcinoid or islet cell carcinoma; patients with carcinoid or islet cell carcinoma associated with multiple endocrine neoplasia (MEN)1 syndrome will be eligible and entered in the islet cell cohort * Patients must have measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded) as \>= 20 mm with conventional techniques or as \>= 10 mm with spiral CT scan * Patients may have received 0 or 1 prior cytotoxic therapy; chemotherapy used as a radiosensitizer will be considered one prior chemotherapy regimen; patient must not have received prior bevacizumab or any other therapy targeting vascular endothelial growth factor (VEGF) or VEGF receptors (i.e., SU11248, PTK787/ZK222584, Sorafenib, GW786034) * Patients must be on a stable dose of somatostatin analogue for 2 months prior to start of protocol; octreotide dose not count toward prior therapy * Prior radiation therapy is permitted; a recovery period of at least 4 weeks after completion of radiotherapy is required prior to enrollment * Patients may have received prior interferon (not counted toward prior cytotoxic chemotherapy) * Patients may have received prior therapy targeting v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (c-kit), c-abl oncogene 1, non-receptor tyrosine kinase (abl), platelet-derived growth factor receptor…