To compare efficacy, survival outcomes and identify prognostic factors of conventional transarterial chemoembolization (cTACE), drug-eluting beads TACE (DEB-TACE), and 90Yttrium-radioembolization (Y90) for the treatment of gastro-entero-pancreatic (GEP) neuroendocrine tumor liver metastases (NELMs).
METHOD AND MATERIALSThis retrospective single center-study included 192 patients (58.6 years mean age, 56% men) with NELM of known GEP origin treated with cTACE (N=122), DEB-TACE (N=26), or Y90 (N=44) between 2000 and 2014. Follow-up imaging studies were compared with baseline imaging to determine the radiologic response. Median overall survival (OS) and hepatic progression-free survival (HPFS) were evaluated. Propensity score analysis (PSA) was performed to minimize selection bias. Survival analysis was calculated using the PS-adjusted Kaplan-Meier method with the PS-adjusted log-rank test and the uni- and multivariate (MVA) Cox proportional hazards model.
RESULTSMedian OS and HPFS were 28.8 and 18.1 months for entire study group, 34.0 and 20.1 months after cTACE, 23.6 and 12.4 months after Y90, 21.7 and 13.3 months after DEB-TACE treatment, respectively. In PSA, cTACE demonstrated significant prolonged median OS compared to Y90 (p=0.035) but not compared to DEB-TACE (p=0.198). Five-year survival time after first intra-arterial treatment (IAT) for cTACE, DEB-TACE and Y90 were 28.2%, 10.3% and 18.5%, respectively. No significant differences in HPFS were seen among evaluated IAT. MVA of the entire study cohort identified extra-hepatic metastasis (HR, 1.63, p<0.01) and tumor burden >50% (HR, 1.93, p<0.01) as predictive for reduced OS whereas 3≥ embolization sessions were related to prolonged OS (HR, 0.59, p<0.05). Among all IAT options the response rates (RR) and the incidence of adverse effects were not significantly different. In MVA, DEB-TACE corresponded with improved RR compared to cTACE (OR, 1.2, p=0.04).
CONCLUSIONDue to significantly improved OS cTACE revealed to be the preferable IAT option compared to Y90. DEB-TACE vs. cTACE and DEB-TACE vs. Y90 appeared equally effective according to OS. Prospective studies are warranted to determined the optimal IAT option for patients with unresectable NELM.
CLINICAL RELEVANCE/APPLICATIONNELM decreases OS dramatically. IAT appealed as an indispensable mainstay in palliative treatment of unresectable NELM to increase OS. Thus, choice of IAT with greatest improved OS still needs to be investigated.