Objective：To investigate the relation between clinicopathology and expression level of vascular endothelial growth factor A (VEGF-A), VEGF-C and placenta growth factor (PIGF) in liver cancer, and evaluate the influence of PIGF expression on recurrence of liver cancer after hepatectomy.
Methods：Tumor specimens of 63 patients with liver cancer who underwent hepatectomy from May 2006 to August 2008 were randomly collected. The expression level of VEGF-A, VEGF-C and PIGF genes in the tumor tissues were detected by real time PCR and the concentrations of PIGF protein in the tumor tissues were determined by ELISA method. The microvessel densities (MVD) of the tumor tissues were assessed by CD34 immunohistochemical staining. The correlations between these angiogenic factors and the clinicopathology of liver cancer as well as early recurrence after hepatectomy were analyzed. The relation between PIGF content and MVD of liver cancer was also observed.
Results：The proportions of high expression of VEGF-A, VEGF-C and PIGF in the HCC patients with early metastasis were 62.5% (10/16), 68.75% (11/16) and 87.5% (14/16), respectively; and the ratio of high expression of PIGF was higher than that of the other two angiogenic factors in the  HCC patients with early metastasis (P＜0.05). The expression levels of VEGF-C and PIGF were associated with AFP level,  proportions of high expression of VEGF-C and PIGF significantly increased when APF level was higher than 245 ng/dL (P＜0.05). The higher the PIGF protein content, the more likely to have an early recurrence in patients at stage II or III (P＜0.05). MVD in patients of stage II and III was higher than that in patients of stage I (P＜0.05), and MVD was positively correlated with the PIGF content (r=0.58, P=0.025) in patients with tumor larger than 5 cm in diameter.
Conclusions：PIGF content of liver cancer patients is closely associated with early recurrence after hepatectomy, especially in the stage II and III  patients. PIGF can be used as an independent predictive factor for early recurrence in advanced liver cancer after hepatectomy.