Prospective phase II study of chemoembolization with drug-eluting beads for hepatic neuroendocrine metastases: Interim analysis.

Abstract

331 Background: To evaluate safety and efficacy of transarterial chemoembolization with doxorubicin eluting beads (DEB-TACE) in 30 patients with hepatic neuroendocrine metastases (NET) in a prospective phase II study. We report the interim analysis on 10 patients. Methods: Patients who met inclusion criteria (NET liver-dominant metastases, ECOG 0-1, treatment naïve) underwent up to 4 DEB-TACE sessions (100-300 micron beads loaded with up to 100mg of doxorubicin) within a 6-month period. Statistical plan included interim analysis of initial 10 patients to assess therapeutic efficacy (defined as objective response≥50%). Tumor response was assessed by MR imaging 1 month after treatment using contrast-enhancement (EASL) and tumor size (RECIST). Safety was assessed by NCI Common Terminology Criteria. Results: DEB-TACE was successfully performed in 10 patients (22 targeted lesions). Patient characteristics included mean age 65 yrs; ECOG 0/1 (6/4); carcinoid syndrome (n=2); tumor burden range (4-75%), and mean targeted tumor size 4.8 cm (range 1.2-10.2). At one month follow-up (n=9), Grade 3 toxicities consisted of hyperglycemia (n=3), abdominal pain (n=3), fatigue (n=1), biloma (n=1) and elevated ALT (n=1). Note that four patients had Grade 2 bilomas, which occurred in the setting of small lesions (<2cm), diffuse disease with very low tumor burden (near military pattern), and single lesion ≥ 5cm. Tumor response using MR imaging at 1 month-follow-up revealed a mean treated tumor decrease in size of 7% (p=0.03), and a mean decrease in contrast-enhancement of 59% (p<0.0001). Using RECIST, partial response was achieved in 1 patient (11%), whereas 8 patients (89%) had stable disease. Using EASL criteria, 7 patients (78%) had objective tumor response and 2 (12%) had stable disease. Conclusions: Interim analysis shows therapeutic efficacy of DEB-TACE in liver-dominant NET metastases. Early recommendation suggests DEB-TACE may be best suited for NET patients with multifocal disease or diffuse disease with large tumor burden. [Table: see text] No significant financial relationships to disclose.