Hepatic artery embolization of liver malignancy increases plasma levels of hepatocyte growth factor and transforming growth factor alpha

To identify early changes in serum growth factor levels following hepatic artery embolization (HAE) of human liver tumors and to determine if changes in circulating growth factors differ between primary and metastatic liver tumors. Whole blood samples from 30 patients scheduled to undergo HAE for primary and metastatic liver malignancies were prospectively collected prior to HAE (12+/-7 days) and immediately after HAE (0.9+/-0.4 days). Samples were analyzed for the following growth factors: hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), transforming growth factor alpha (TGFA), and transforming growth factor beta-1 (TGFB-1). Of the patients receiving HAE, 6 patients had primary liver tumors (5 hepatocellular carcinoma, 1 cholangiocarcinoma). Twenty-four patients underwent HAE for liver metastases from neuroendocrine tumor (n=16) or other malignancies (n=8, sarcoma, melanoma, colorectal, and breast). Paired t-tests were performed for the growth factors of interest before and after embolization with sub-group analyses of patients with primary and metastatic liver tumors. There was a significant increase in the plasma level of HGF post-HAE when compared to pre-HAE levels (2.0+/-1.5 fold, p=0.0001). TGFA levels also showed a significant increase post-HAE (2.0 +/-2.3 fold, p=0.02). Plasma levels of VEGF, EGF, and TGFB1 were not significantly changed post-HAE. In post-hoc subgroup analysis, patients with primary liver tumors showed significantly reduced levels of TGFB1 post-HAE (0.7 +/-0.3 fold, p=0.02). Increased VEGF levels in neuroendocrine cancer patients immediately after HAE approached statistical significance (1.7 +/-1.3 fold, p=0.13). Hepatocyte growth factor and transforming growth factor alpha increase after hepatic artery embolization of both primary and metastatic hepatic malignancy. Post-embolization growth factor levels appear to differ between tumor subtypes.