BACKGROUND: The role of debulking surgery in metastatic nonfunctioning pancreatic endocrine carcinomas (M-NF-PECs) with resectable primary tumour and unresectable liver metastases is debated. AIM: Aim of the study is to evaluate whether the resection of the primary tumour in metastatic nonfunctioning pancreatic endocrine carcinoma improves survival. PATIENTS AND METHODS: Fifty-one metastatic nonfunctioning pancreatic endocrine carcinoma patients with unresectable liver metastases were enrolled from 1990 to 2004 at the time of diagnosis. Nineteen patients underwent complete resection of the primary tumour whilst 32 were judged unresectable. All cases were classified according to the WHO 2000 classification. All clinico-pathological parameters, including grade of differentiation and the Ki-67 proliferation index were considered in univariate and multivariate models. RESULTS: Of the 19 resected patients, 14 (73.7%) underwent left-pancreatectomy and 5 (26.3%) pancreaticoduodenectomy. In the unresected group of 32 patients, 9 (28.1%) underwent surgical biliary and/or gastric by-pass. There was no postoperative mortality and the median survival was 54.3 months (95% CI: 25.7-82.9). No difference in survival was observed between the two groups [resected: median 54.3 months (95% CI: 25-83.6), unresected: median 39.5 months (95% CI: 5.4-73.6); p=0.74]. Upon multivariate analysis poor differentiation (HR 3.01; 95% CI 1.08-8.4; p=0.035) and a Ki-67 index >/=10% (HR 4.4; 95% CI 1.2-16.1; p=0.023) were significant predictors of survival. CONCLUSIONS: Resection of the primary pancreatic tumour in metastatic nonfunctioning pancreatic endocrine carcinoma patients with unresectable liver metastases does not significantly improve survival. Resection can be considered as symptomatic palliative therapy in patients with well-differentiated endocrine carcinomas and a proliferative index lower than 10%.