Therapy for Metastatic Disease: Ileum

The ileum is one of the most common primary sites for neuroendocrine tumours and the most common site of GI NETs. Approximately half will present as locoregionally advanced or metastatic disease. Patients with ileal NETs can vary widely in terms of their clinical course, based on underlying histopathological factors and patient characteristics. Recently, large international randomised trials have reported significant progress in the treatment of ileal NETs for the following therapies: somatostatin analogues, the mTOR inhibitor everolimus and peptide receptor radionuclide therapy (PRRT). Other treatments such as debulking surgery, liver-directed therapy chemotherapy and interferon (IFN) are commonly used albeit with less evidence base. There are few randomised trials in Grade 3 NETs or neuroendocrine carcinoma (NEC), but chemotherapy is the mainstay of systemic treatment for this patient group. Issues remain in defining the optimal sequencing of therapies and detecting of changes in disease that should trigger changes in therapy. The increasing use of functional imaging gives clinicians a greater understanding of individual tumour biology and disease burden. Further research is needed to probe the molecular characteristics across the spectrum of NETs, to allow optimisation of current systemic therapies and develop even more effective approaches.