Palliative resection of the primary tumor in 442 metastasized neuroendocrine tumors of the pancreas: a population-based, propensity score-matched survival analysis

There is an ongoing debate on whether palliative removal of the primary tumor may result in a survival benefit for patients with incurable stage IV pancreatic neuroendocrine tumors (P-NET). The objective of this study was to assess whether palliative resection of the primary tumor in patients with incurable stage IV P-NET has an impact on survival. Patients with stage IV P-NET registered in the Surveillance, Epidemiology, and End Results database between 2004 and 2011 were identified. Those undergoing resection of metastases were excluded. Overall and cancer-specific survival of patients who did and did not undergo resection of their primary tumor were compared by means of risk-adjusted Cox proportional hazard regression analysis and propensity score-matched analysis. A total of 442 stage IV P-NET patients were identified, of whom 75 (17.0 %) underwent palliative primary tumor resection. The latter showed a significant benefit in both overall survival (hazard ratio [HR] of death = 0.41, 95 % confidence interval [CI] 0.25-0.66, p < 0.001) and cancer-specific survival (HR of death = 0.41, 95 % CI 0.25-0.67, p < 0.001) in unadjusted multivariate Cox regression analysis; the benefit persisted after propensity score adjustment. This population-based analysis of stage IV P-NET patients provides compelling evidence that palliative resection of the primary tumor is associated with significant survival benefit. Thus, the recent recommendations judging resection of the primary as inadvisable and the accompanying trend towards fewer palliative resections of the primary tumor have to be contested.