Debulking metastases of pancreatic neuroendocrine tumors (PNETs) may be effective at a threshold of greater than or equal to 70%, indicating that liver debulking criteria could possibly be extend to this threshold, according to a recent study.
PNETs are known to metastasize to the liver, often leading to death by liver failure. However, debulking neuroendocrine liver metastases may improve survival among individuals with PNETs.
Rosemary E Morgan, MD, Oregon Health & Science University, and colleagues evaluated liver debulking at a threshold of 70% instead of 90% in patients with carcinoid liver metastases, of whom a small number had PNETs. They also assessed the use of liver debulking with a threshold of 70% in 42 patients (44 operations) with PNETs who underwent surgery between 2006 and 2016. Median follow-up in the second cohort lasted 33 months.
Results of the study indicated that, in the first cohort, first-year survival was 90%. The percent of hepatic disease resected had resulted in no differences in liver progression or survival. Furthermore, metastasis size, number, grade, or the presence of extrahepatic metastases did not result in any differences in outcomes.
In the second cohort, 24 of 44 operations resulted in 100% debulking, while 12 resulted in 90% or greater debulking, and 8 resulted in 70% or greater debulking. At approximately 33 months follow-up, median progression-free survival was 11 months, and 5-year overall survival was 81%.
Researchers noted that the percent debulked did not lead to any significant differences in outcomes. In addition, only liver metastases of 5 cm or more were associated with liver progression-free and overall survival.
“The results of the present series show that on both univariate and multivariate analyses, patients had outcomes that were indistinguishable based on percentage of gross hepatic disease debulked, providing additional support to extend the threshold of 70% for debulking to PNET liver metastases,” researchers concluded.—Christina Vogt