2014[50] 12 PNENs 38 TAE/37 TACE Post-embolization syndrome 6 (40%) TAE 0%   16 NENs ileum   Post-embolization syndrome 8 (60%) TACE     2 NENs colon   *Cumulative results. Conclusions TAE appears to be an optimal treatment approach for inoperable liver metastases from NENs, for higher metastatic load, for management of symptoms alone and in association with interferon or somatostatin

analogues, suggesting a prolonged 5-yr selleck chemicals survival and local tumor control and for survival improvement [42, 43, 45, 51]. Tumor Selleck Bafilomycin A1 response as well as survival, but not clinical and biochemical response, appear to be better for patients with carcinoid than pancreatic NENs. TAE is considered a safe procedure. The low number of complications during and/or after TAE procedures can be easily and quickly treated, while the small number of deaths further confirms the safety of this technique. Moreover the deaths are often associated with adverse effects not related to TAE, but with the chemotherapeutic agents used for CDK inhibitor TACE. It is essential that TAE is performed by highly qualified and specialized team. Finally, the presence of extra-hepatic metastases or unresected primary tumor should not limit the use of TAE [48] since the liver function plays the most important role in the survival of these patients. On the other hand, TAE should be avoided in patients with massive tumor burden and severely compromised liver function, poor

performance status, sepsis, carcinoid heart disease and other risk factors for treatment

related mortality (Table  4). In these cases less aggressive TAE, repeated if needed, can be effective, while decreasing the risk for procedure related mortality [49, 50]. Table 4 Indications and contraindications of TAE in patients with NENs Indications Contraindications – NEN tumor functioning or not – Massive tumor burden – Highly vascularised liver metastases – Severely compromised liver function – Liver metastases >3 in number and or >3 cm in size – Poor performance status – Sepsis – Patients with tumor mass-related symptoms and/or carcinoid syndrome – Carcinoid heart disease and other risk factors for treatment related mortality Future randomized, prospective clinical Axenfeld syndrome trials comparing safety, efficacy and lorng term outcomes of different treatment approaches for liver metastases in NEN patients with comparable disease, should better define the role of TAE. In conclusion, available data suggest TAE as a safe therapeutic option in patiens with liver metastases from NENs, effective for controlling tumor progression and improving mass and endocrine symptoms, while increasing long term survival. In order to minimize risk related procedure TAE should be performed in a multidisciplinary setting and in experienced NEN centers. Finally, the choice of TAE instead of TACE, PRRT, chemotherapy or biotherapy should be performed in a multidisciplinary setting and in experienced NEN centers, according to patient and tumor characteristics.