D. S. Strosberg1, J. Onesti4, N. Saunders3, G. Davidson1, M. Shah5, M. Dillhoff1, C. Schmidt1, M. Bloomston2, L. A. Shirley1 1The Ohio State University Wexner Medical Center,Surgical Oncology,Columbus, OH, USA 221st Century Oncology,Fort Meyers, FL, USA 3Emory University School Of Medicine,Atlanta, GA, USA 4Mercy Health Grand Rapids,Grand Rapids, MI, USA 5The Ohio State University Wexner Medical Center,Medical Oncology,Columbus, OH, USA
Introduction: Transarterial chemoembolization (TACE) is a viable treatment option for patients with metastatic neuroendocrine tumors (NETs) to control tumor progression and palliate symptoms of hormone excess. Pancreastatin, a split product of chromogranin, has been shown to correlate with survival in patients with NETs. The objective of this study was to investigate the prognostic impact of pancreastatin levels in patients with metastatic NETs treated with TACE.
Methods: Patients with metastatic NET treated with TACE at a single institution from 2000 to 2013 were analyzed. Clinical variables were analyzed with Chi-square, Fisher Exact, or independent T-test as appropriate. Kaplan-Meier curves for overall survival (OS) were analyzed using log-rank testing for curve differences.
Results: 188 patients underwent TACE for metastatic NETs during the study period. An initial pancreastatin level greater than 5000 pg/mL correlated with worse OS from time of first TACE (Median OS 58.5 months vs 22.1 months, p<0.001). A decrease in pancreastatin levels by 50% or more after TACE treatment correlated with improved OS (Median OS 53.8 months 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 (percent of patient with increase 78.1% vs 55.2%, p=0.002). Patients who had an increase in pancreastatin levels after initial drop post-TACE were also more likely to have liver progression on axial imaging (70.7% vs 40.7%, p=0.005) as well as more likely to need repeat TACE (21.1% vs 6.7%, p=0.009).
Conclusion: For patients with liver metastases from NET, measurement of pancreastatin levels can be useful in several steps during potential TACE treatment. Extreme high levels prior to TACE can predict poor outcomes, significant drops in pancreastatin after TACE correlate with improved survival, and a rise in levels after initial drop may predict progressive liver disease requiring repeat TACE. As such, pancreastatin levels should be measured throughout the TACE treatment period.
