Identifying Prognostic Factors for Well-Differentiated Metastatic Pancreatic Neuroendocrine Tumours: A Retrospective...

Pancreatic neuroendocrine tumours (pNETs) represent rare neoplasms of all NETs often presenting without functional activity. Many sporadic non-functioning pNET patients are already metastatic at the time of diagnosis, and the therapeutic approach to such patients is mostly palliative. In this international, multicentre, retrospective cohort study, we assessed the prognostic value of a set of anthropometric, clinical, biochemical, radiological and pathological parameters at baseline and the impact of the therapeutic strategies on the survival of patients with sporadic grade 1/2, stage IV, non-functioning pNETs. Three hundred and twelve consecutive patients diagnosed between 1993 and 2010 were included. The median overall survival (OS) was 6.6 years and survival at 5 and 10 years was 62 and 34% respectively. On univariate analysis, Eastern Cooperative Oncology Group (ECOG) status ≥2, grade 2, bilobar hepatic metastases, synchronous metastases, and high chromogranin A, alkaline-phosphatase and lactic-dehydrogenase were associated with a significant reduction of OS. Palliative/curative surgery and loco-regional hepatic interventions were significant factors improving OS. On multivariate analysis, ECOG status ≥2, synchronous metastases, Ki-67 ≥10%, and high alkaline-phosphatase correlated significantly with an increased risk of death. Both palliative/curative surgery and loco-regional hepatic interventions had a positive impact on OS. Although most parameters did not prove to be independent OS predictors at multivariate analysis, they showed a tendency towards that. Future prospective studies including larger patient populations may give greater clarity. We believe the integration of these parameters has the potential to provide a reliable prognostic score for the stratification of patients with sporadic well-differentiated metastatic non-functioning pNETs.