Prognostic factors at diagnosis and value of WHO classification in a mono-institutional series of 180 non-functioning pancreatic endocrine tumours

BACKGROUND: Non-functioning pancreatic endocrine tumours (NF-PETs) are an aggressive gastroenteropancreatic neoplasm. The present study assessed survival, value of World Health Organisation (WHO) classification and prognostic utility of clinicopathological parameters at diagnosis. PATIENTS AND METHODS: From 1990 to 2004, 180 patients with NF-PETs were entered in a prospective database, and predictors of prognosis were tested in uni- and multivariate models. RESULTS: There were 25 (14\%) benign lesions, 38 (21\%) neoplasms of uncertain behaviour, 100 well-differentiated carcinomas (56\%) and 17 poorly differentiated carcinomas (9\%). Radical resection was possible in 93 cases (51.6\%). Overall 5-, 10- and 15-year survival rates were 67\%, 49.3\% and 32.8\%, respectively, and were significantly higher in radically resected patients (93\%, 80.8\% and 65.2\%, respectively; P < 0.00001). By multivariate analysis, poor differentiation [hazard ratio (HR) 7.3; P = 0.0001], nodal metastases (HR 3.05; P = 0.02), liver metastases (HR 3.29; P = 0.003), K(i)-67 >5\% (HR 2.5; P = 0.012) and weight loss (HR 3.06; P = 0.001) were significantly associated with mortality. CONCLUSION: This study confirms the good long-term survival of patients with NF-PETs and the prognostic value of WHO classification, liver metastases, poor differentiation, Ki-67, nodal metastases and weight loss. These latter two parameters have a prognostic value similar to that of liver metastases and Ki-67.