Metformin seems to have anti-cancer effects. However, it is not clear whether use of glycemia and metformin affect outcomes of patients with advanced pancreatic neuroendocrine tumors (pNETs). We investigated the association between glycemia and progression-free survival (PFS) of patients with NETs treated with everolimus and/or somatostatin analogues, as well as the association between metformin use and PFS time.