Tyrosine Kinase Inhibitors and Immunotherapy Updates in Neuroendocrine Neoplasms

Neuroendocrine tumors (NETs) represent a heterogeneous group of malignancies that arise from neuroendocrine cells dispersed throughout the organs/tissues of the body. Treatment of advanced/metastatic disease varies depending on tumor origin and grade. Somatostatin analogs (SSA) have been the mainstay first-line treatment in the advanced/metastatic setting for tumor control and managing hormonal syndromes. Treatments beyond SSAs have expanded to include everolimus (mTOR inhibitor), tyrosine kinase inhibitors (TKI) (e.g., sunitinib), and peptide receptor radionuclide therapy (PRRT) with the choice of therapy to some extent dictated by the anatomic origin of the NETs. This review will focus on emerging systemic treatments for advanced/metastatic NETs, particularly TKIs, and immunotherapy.