Prognostic Impact of Serum Pancreastatin Following Chemoembolization for Neuroendocrine Tumors.

Purpose: The objective of this study was to investigate the prognostic impact of the biomarker serum pancreastatin in patients with metastatic neuroendocrine tumors (NETs) treated with transarterial chemoembolization (TACE).

Methods: Patients with metastatic NET treated with TACE at a single institution from 2000 to 2013 were analyzed. Patient demographics, response to therapy, and long-term survival were compared with baseline pancreastatin level and changes in pancreastatin levels after TACE.

Results: A total of 188 patients underwent TACE during the study period. An initial pancreastatin level greater than 5000 pg/mL correlated with worse overall survival (OS) from time of first TACE (median OS, 58.5 vs. 22.1 months, p < 0.001). A decrease in pancreastatin level by 50% or more after TACE treatment correlated with improved OS (median OS 53.8 vs. 29.9 months, p = 0.032). Patients with carcinoid syndrome were more likely to have a subsequent increase in pancreastatin after initial drop post-TACE (78.1 vs. 55.2%, p = 0.002). Patients with an increase in pancreastatin levels after initial drop post-TACE were more likely to have liver progression on imaging (70.7 vs. 40.7%, p = 0.005) and more likely to need repeat TACE (21.1 vs. 6.7%, p = 0.009).

Conclusions: For patients with liver metastases from NET treated with TACE, pancreastatin measurement may be a useful prognostic indicator. Extreme high levels before TACE can predict poor outcomes, whereas significant drops in pancreastatin after TACE correlate with improved survival. An increase in levels after initial decrease may predict progressive liver disease requiring repeat TACE. As such, pancreastatin levels should be measured throughout the TACE treatment period.