Management of Gastro-intestinal Neuroendocrine Tumors with Liver Metastases: A Comprehensive Review

Neuroendocrine tumors have been studied for over a century and several advances have been made in under- standing of the pathophysiology, diagnostic methods, management, and underlying genetics. Advances in pathology and identification of serum markers have helped to identify subsets of tumors. Diagnostic modalities like somatostatin receptor scintigraphy (SRS) with CT fusion imaging, Endoscopic ultrasonography (EUS), PET scan and MRI have vastly im- proved the diagnosis of these tumors. The management of these tumors requires a multidisciplinary approach including endocrinology, interventional radiology, medical surgery, and medical & radiation oncology. The aggressive use of cura- tive and cytoreductive surgery, orthotopic liver transplantation as well as interventional radiological techniques including embolization, chemo-embolization, and radiofrequency ablation in conjunction with judicial use of somatostatin analogues for symptom control has become the frontline of treatment. For the vast majority of patients with unresectable metastatic disease, older chemotherapeutic agents have shown disappointing results, yet new regimens and new classes of drugs hold great promise. Clinicians need to be aware with the disease pattern, natural history and disease progression, which are characteristic of these tumors. A multidisciplinary approach is the evidence based logical approach to treat these diseases.