Increased vascular endothelial growth factor transcription in residual hepatocellular carcinoma after open versus laparoscopic hepatectomy in a small animal model

Abstract

Vascular endothelial growth factor (VEGF) is overexpressed in hepatocellular carcinoma (HCC), and findings have shown that its upregulation in these tumors has an impact on tumor growth. The authors hypothesized that compared with open liver resection, laparoscopic hepatectomy would result in a decreased local angiogenic response in residual tumor cells. Right- and left-lobe hepatomas were induced in Buffalo rats via laparoscopically guided subcapsular injection of Morris hepatoma cells. After 1 week, the animals were randomized to laparoscopic or open left lateral hepatectomy. In 14 days after resection, the rats were killed, the residual right lobe tumors were measured, and tissue was procured for RNA extraction. Transcript levels of VEGF messenger RNA (mRNA) were quantified with reverse transcriptase-polymerase chain reaction (RT-PCR), and VEGF serum levels were measured by enzyme-linked immunoassay (ELISA) both before resection and at the time of tissue harvest. None of the animals had development satellite liver lesions or distant metastases in the abdomen or thorax. The median residual tumor volume was 320 mm(3) in the open group compared with 180 mm(3) in the laparoscopic group (p = 0.164). The animals that underwent open resection had a 1.3-fold increase in VEGF mRNA transcript levels compared with the laparoscopic resection group (p = 0.008). The serum VEGF levels were not significantly different between the laparoscopic and open groups at baseline (open tumor resection [OR], 23.7 +/- 12.0 pg/ml; laparoscopic tumor resection [LR], 30.7 +/- 15.5 pg/ml; p = 0.334) nor at the time of tissue harvest (OR, 19.9 +/- 19.6 pg/ml; LR, 26.9 +/- 34.5 pg/ml; p = 0.549). Laparoscopic hepatic resection produces decreased VEGF mRNA expression in residual hepatoma cells compared with open resection. Decreased stimulation of angiogenesis promoters in the tumor microenvironment after minimally invasive liver resection may contribute to a lower residual disease burden and ultimately lead to a lower recurrence rate.