Recent advances in the management of gastroenteropancreatic neuroendocrine tumors: insights from the 2017 ASCO Gastrointestinal Cancers Symposium.

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare malignancies that originate in the gastrointestinal system. GEP-NETs are typically indolent, but tumors known as "functional" secrete hormones that can lead to a complex of symptoms, including flushing, diarrhea, bronchospasm, and valvular heart disease. Management of patients with GEP-NETs requires a multidisciplinary approach, as treatment modalities include surgery, radiology, and pharmacotherapy. The available pharmacologic agents have increased in recently, and now include cytotoxic chemotherapies, somatostatin analogues, multitargeted tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, and radioisotopic radiotherapies. The optimal sequencing of treatments is unknown. Advances in the management of GEP-NETs have been based on the results of recently completed clinical trials that have shown improvement in disease outcome and symptom management. The amount of positive data that has emerged from these studies is unprecedented in the GEP-NETs field. At the 2017 American Society of Clinical Oncology Gastrointestinal Cancers Symposium, several abstracts provided subanalyses of previous trials and new data for emerging treatments. Management will likely evolve as these therapies are incorporated into clinical care.