Effect of metastatic site on survival in patients with neuroendocrine neoplasms (NENs). An analysis of SEER data from 2010 to 2014

BACKGROUND: Neuroendocrine neoplasms (NENs) display variable behaviors based on origin and grade. We assumed that both tumor origin and the location of metastasis may play a role in survival. METHODS: We queried the SEER database (2010–2014) for patients with an established diagnosis of NENs and documented site of metastasis and identified 2005 patients. Overall survival (OS) at the time points were estimated by the Kaplan-Meier method Cox proportional-hazards models were used to evaluate the relationship of the interested variables and OS. RESULTS: Lung, liver, bone and brain metastases were observed in 9, 77, 7 and 6% of metastatic patients respectively. In the multivariate model, metastasis locations were significantly associated with worse survival (liver HR: 1.677 (1.226–2.294); (bone metastasis HR: 1.412 (0.965–2.065); brain HR: 1.666 (1.177–2.357)). We produced a scoring system based on site of origin, metastasis location, age, gender, histology and tumor size that can stratify metastatic NEN patients in low, intermediate and high-risk categories to help physicians with decision making. CONCLUSION: Site of metastasis plays an important role in survival of metastatic NEN patients independent of commonly described prognostic factors and should be considered in survival estimates.