New targeted agents in gastroenteropancreatic neuroendocrine tumors.

Neuroendocrine carcinomas are rare neoplasms although of increasing incidence and concern. While traditionally considered of indolent nature, once they progress beyond surgical resectability, the outcome is ultimately fatal for the majority of patients. Somatostatin analogs are useful to control symptoms in functioning tumors and may slow tumor progression in certain disease settings, but sensitivity to conventional cytotoxic chemotherapy is rather limited. In this context, results of the recently published randomized trials with sunitinib and everolimus have demonstrated for the first time that there are agents able to positively impact on the natural history of this complex disease. In this review, we will discuss available data on angiogenesis and mammalian target of rapamycin inhibitors for the treatment of advanced well-differentiated gastroenteropancreatic neuroendocrine tumors.