Pancreatic neuroendocrine and carcinoid tumors: what's new, what's old, and what's different?

Well-differentiated neuroendocrine tumors (NETs) can be subdivided into carcinoid and pancreatic NETs (panNETs). Recently, two therapies have been FDA approved for progressive well-differentiated pancreatic NETs but have not been submitted for use in carcinoid tumors (Yao, Shah, Ito, et al. N Engl J Med 364:514-23, 2011••; Raymond, Dahan, Raoul, et al. N Engl J Med 364:501-13, 2011••). The first is sunitinib (Sutent(®), Pfizer, Inc.), an orally administered, multitargeted receptor kinase inhibitor. The second targeted agent is everolimus (Afinitor(®), Novartis Pharmaceuticals), a mammalian target of rapamycin (mTOR) inhibitor (Yao, Shah, Ito, et al. N Engl J Med 364:514-23, 2011••). Both agents demonstrated improved progression-free survival but can also result in non-trivial toxicities and therefore, should only be considered in patients with progressing or symptomatic pancreatic NET. This review will discuss "new" NET therapies and provides an overview of liver directed and "older" cytotoxic treatment options. We also briefly outline "what's different" by describing a recent genetics report identifying genetic mutations in panNETs. Such a discovery could potentially be used to stratify treatment and such studies are currently being investigated.