Efficacy and safety of combined transarterial embolization/chemoembolization and hepatic arterial infusion chemotherapy versus transarterial embolization/chemoembolization alone in unresectable neuroendocrine tumor liver metastases.

e16309 Background: Neuroendocrine Tumor Liver Metastases (NETLM) represent the most critical prognostic factor in patients with disseminated neuroendocrine tumors, frequently leading to significant morbidity and mortality. For patients with unresectable NETLM, locoregional therapies targeting the liver are essential for disease management and symptom palliation. Transarterial embolization (TAE) and transarterial chemoembolization (TACE) are established locoregional therapies for unresectable neuroendocrine tumor liver metastases (NETLM). The potential survival benefit of adding hepatic arterial infusion chemotherapy (HAIC) to these therapies remains unclear. This study aimed to compare the efficacy and safety of TAE/TACE alone versus TAE/TACE combined with HAIC (TAE/TACE+HAIC) in patients with unresectable NETLM. Methods: A retrospective analysis was conducted on 101 patients with unresectable NETLM treated at Peking University Cancer Hospital between February 2012 and November 2024. Of these, 67 patients received TAE/TACE alone and 34 patients received TAE/TACE+HAIC. Propensity score matching (PSM) was employed to minimize selection bias. The primary endpoint was progression-free survival (PFS) and secondary endpoints included hepatic progression-free survival (hPFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR) and safety. Results: PSM resulted in 21 patient pairs with comparable baseline characteristics between TAE/TACE and TAE/TACE+HAIC cohorts. Among these patients, 5 were classified as G1, 33 as G2, and 4 as G3. TAE/TACE matched cohort exhibited a higher median OS compared with the TAE/TACE+HAIC cohort(71.3 months vs. 34.2 months; P = 0.01), while hPFS (15.8 months vs. 14.9 months; P = 0.7) and PFS (11.7 months vs. 11.2 months; P = 0.9) were similar. ORR and DCR did not differ significantly (ORR: 42.9% vs. 57.1%, P = 0.54; DCR: 100% vs. 95.2%, P = 1.0). The patients underwent a total of 233 treatments. No treatment-related deaths occurred and serious adverse events were comparable, except for higher rates of elevated transaminases (14.5% vs. 4.5%; P = 0.02) and hyperbilirubinemia (5.3% vs. 0%; P = 0.01) in the combined group. Conclusions: TAE/TACE alone was associated with superior survival outcomes and a more favorable safety profile in patients with unresectable NETLM. These findings suggest that TAE/TACE alone may be a more effective and safer treatment approach for this patient population. The combination therapy should be approached with caution due to unimproved survival outcomes and increased liver-related toxicities.