03:09 PM Abstract No. 317 Prolonged survival after treatment of hepatic uveal melanoma metastases using immunoembolization

Abstract

Control of uveal melanoma (UM) liver metastases is essential to prolonging overall survival (OS). At our institution, immunoembolization (IE) is considered a 1st line liver-directed therapy (LDT) for those with <50% hepatic tumor burden. A subset of patients experience a prolonged OS of ≥3 years with IE. The purpose of this study is to identify potential characteristics favoring prolonged OS. This is a single-institution IRB -exempt retrospective study of 174 patients (median age 60, range 26-87; 86 female) who initiated IE treatment for UM hepatic metastasis from 6/2005-12/2014. EMR, PACS, and an internal UM database were reviewed for primary tumor characteristics, genetics, and treatment modality; metastatic disease characteristics; IR treatment history; adjuvant therapies; and OS. Patients were divided into 2 groups; patients who survived ≥3 years (Group A; n=28; 19 female) and those who survived <3 years (Group B; n=146; 67 female) Kaplan-Meier, unpaired t-test and chi square test were used for data analysis. Median OS (n=174) was 16.8 months (range, 2.1-94.8). OS was 70.1% at 1 year, 32.8% at 2 years, 16.1% at 3 years, 10.9% at 4 years, 5.2% at 5 years, 3.4% at 6 years, and 1.7% at 7 years. Median OS for Group A was 52.4 months (range 38.1-94.8) and for Group B, 15.4 months (range 2.1-34.3). Significant differences (p<0.05) were found in several categories. Group A was less likely to undergo enucleation, more likely to be female, had a longer interval before detection of hepatic metastasis and a longer interval between onset of hepatic metastasis and 1st IE. Group A was also more likely to be treated with IE only, have a longer time interval before changing LDT, have treatment breaks, achieve partial response/stable disease following completion of first IE, and less likely to undergo chemoembolization as 2nd line LDT. Specific characteristics were identified that favor a prolonged OS for patients with UM hepatic metastases.