Molecular pathogenesis of neuroendocrine tumors: implications for current and future therapeutic approaches.

The treatment landscape and biologic understanding of neuroendocrine tumors (NET) has shifted dramatically in recent years. Recent studies have shown that somatostatin analogues have the potential not only to control symptoms of hormone hypersecretion but also have the ability to slow tumor growth in patients with advanced carcinoid. The results of clinical trials have further shown that the VEGF pathway inhibitor sunitinib and the mTOR inhibitor everolimus have efficacy in patients with advanced pancreatic NETs. The efficacy of these targeted therapies in NET suggests that the molecular characterization of NETs may provide an avenue to predict both which patients may benefit most from the treatment and to overcome potential drug resistance. Recent genomic studies of NETs have further suggested that pathways regulating chromatin remodeling and epigenetic modification may play a key role in regulating NET growth. These observations offer the potential for new therapeutic and diagnostic advances for patients with NET.