Effective cytoreduction can be achieved in patients with numerous neuroendocrine tumor liver metastases (NETLMs)

Background: Cytoreductive surgery for neuroendocrine tumor liver metastases improves survival and symptomatic control. However, the feasibility of adequate cytoreduction in patients with many liver metastases remains uncertain. We compared patient outcomes based on the number of lesions treated to better define the efficacy of cytoreductive surgery for numerous neuroendocrine tumor liver metastases. Methods: Patients undergoing hepatic cytoreductive surgery for gastroenteropancreatic neuroendocrine tumors were identified in our institutional surgical neuroendocrine tumor database. Imaging studies were reviewed to determine the liver tumor burden and percent cytoreduced. Overall survival and progression free survival were compared, using the number of lesions treated, percent tumor debulked, and additional clinicopathologic characteristics. Results: A total of 188 hepatic cytoreductive procedures were identified and stratified into groups according to the number of metastases treated: 1-5, 6-10, and > 10. Median overall survival and progression free survival were 89.4 and 22.5 months, respectively, and did not differ significantly between groups. Greater than 70% cytoreduction was associated with significantly better overall survival than <70% cytoreduction (134 months versus 38 months). Conclusion: In patients with gastroenteropancreatic neuroendocrine tumors and liver metastases, >70% cytoreduction led to improved overall survival and progression-free survival and was achieved reliably in patients undergoing debulking of >10 lesions. These data support an aggressive approach to patients with numerous neuroendocrine tumor liver metastases to achieve >70% cytoreduction. (C) 2018 Elsevier Inc. All rights reserved.