Expanded criteria for debulking of liver metastasis also apply to pancreatic neuroendocrine tumors

Background Recently, there has been a move toward decreasing the threshold for liver debulking for metastatic carcinoid tumors from 90% to 70%. The debulking threshold and factors that predict outcomes of liver debulking operations specifically among pancreatic neuroendocrine tumors are not well defined. Methods Records of patients with pancreatic neuroendocrine tumors undergoing liver debulking with a threshold of 70% from 2006 to 2016 were reviewed. Extrahepatic metastases and positive margins by enucleation were allowed. Liver progression-free survival and overall survival were calculated by the Kaplan-Meier method for various factors and compared by log-rank. Factors also were correlated with liver progression-free survival and overall survival by multivariate regression analyses. Results Forty-two patients underwent 44 operations, of which 24 resulted in 100% debulking, 12 resulted in ≥90% debulking, and 8 resulted in ≥70% debulking. Median liver progression-free survival was 11 months. The 5-year overall survival rate was 81%. There were no significant differences in outcome based on percent debulked. Only liver metastasis ≥5 cm correlated with liver progression-free survival and overall survival. Conclusion Consideration should be given to expanding the criteria for liver debulking in pancreatic neuroendocrine tumors to include a new threshold of >70% debulking, intermediate grade tumors, positive margins, and extrahepatic metastases; these criteria yield results indistinguishable from complete resection. Using these expanded criteria will increase the number of patients eligible for an operation and maintain high survival rates.