4:12 PM Abstract No. 369 Tumor progression and resection candidacy after portal vein embolization

To evaluate achievement of resection candidacy after portal vein embolization (PVE) as a function of tumor burden and cell type. 49 patients (mean age 64, 73% males) underwent PVE from 2008-16 to induce hypertrophy in inadequately sized future liver remnants (FLR). Patients had hepatocellular carcinoma (HCC, n = 13), metastatic neuroendocrine tumor (mNET, n = 4), metastatic colorectal cancer (mCRC, n = 17), or metastatic gall bladder/cholangiocarcinoma (GB/CC, n = 15). Pre- and post-PVE volumetric assessment was performed for tumor, embolized regions, and FLR. Tumor progression within embolized regions and FLR was measured, and clinical outcomes were evaluated. 17 (35%) patients failed to proceed to resection (HCC = 2 (15%), mNET = 2 (50%), mCRC = 8 (47%), GB/CC = 5 (33%), p = 0.2). Reasons for failure to achieve candidacy were tumor progression in 12 (mCRC = 8, GB/CC = 3, HCC = 1), clinical deterioration in 3 (mNET = 1, HCC = 1, GB/CC = 1), and inadequate FLR in 2 (mNET = 1, GB/CC = 1). Although adequate hypertrophy was achieved in most of the failure patients, (mean FLR hypertrophy of 42%, from 581 to 765 ml, p = 0.012), mean tumor volume also increased, from 306 to 535 ml, (p = 0.03). With progression encroaching or crossing the resection margin classified as ipsilateral progression, only a tiny fraction of the total tumor burden and progression occurred within the FLR (3 to 6 ml, p = 0.2). Tumor progression was the major factor for failure for mCRC, with significant increases in tumor burden (p = <0.001). mCRC patients who progressed and failed had larger baseline tumor burdens (416 vs 104 ml, p = 0.008). 32 (65%) patients were resected at a mean of 53 ± 19 d after PVE (mean FLR hypertrophy 67%, from 560 to 863 ml, p