In a retrospective study of patients with pNETs, we found a significant association between metformin use and longer PFS.

Tumor size >15.5 mm, grading G2, and presence of lymphovascular infiltration are factors independently related to nodal metastases in appendiceal NETs. Presence of ≥1 of these features should be considered an indication for oncological radicalization. Although these results represent the largest study currently available, prospective validation is needed.

According to our results, MGMT methylation status, evaluated with methylation specific-polymerase chain reaction or pyrosequencing, should have an important role in patients with metastatic NENs, in order to guide therapeutic options. These results need further confirmation with prospective studies.

dNENs prognosis may be highly variable. These tumors can be metastatic in up to 50% of cases at the time of first diagnosis and can develop metastases thereafter. Functioning neoplasms express high metastatic potential. Nuclear imaging should be performed to exclude distant metastases in all dNENs. Endoscopy and surgery play a primary role in the management of the disease. Further prospective studies are needed.

No abstract