AIM:After transarterial chemoembolization (TACE),theresidual cancer cells are under extensive hypoxic or evenanoxic environment.Hypoxia can lead to adaptive responses.For example,angiogenesis will help these cells survive.Inthis study,we examined the effect of TACE on angiogenesisand expression of vascular endothelial growth factor (VEGF)and basic fibroblast growth factor (b-FGF) and to assesstheir relevance to Walker-256 transplanted hepatoma.METHODS:Male Wistar rats were inoculated with Walker-256 tumor in the left lobe of liver.Angiography andtransarterial chemoembolization were performed at d14 aftertransplantation.Sixty rats bearing walker-256 transplantedhepatoma were randomly divided into control group,arterialinfusion group and TACE group.Each group consisted oftwenty rats.Normal saline,5-Fu,5-Fu and lipiodol wereinfused through hepatic artery respectively.Two weeks afterthe infusion,staining of factor Ⅷ,VEGF and b-FGF wasperformed by immunohistochemistry method in routineparaffin-embeded sections.Microvessel density (MVD) wascounted in endothelial cells with positive factor Ⅷ.Theirexpression levels were analyzed in conjunction with thepathologic features.RESULTS:While a smaller tumor volume was found in TACEgroup (F=37.818,P<0.001),no statistical differencesbetween MVD and expression of VEGF and b-FGF were foundamong the 3 groups.MVD of the control group,chemotherapygroup and chemoemoblization group was 80.84±24.24,83.05±20.29 and 85.20±23.91 (F=0.193,P=0.873),respectively.The positive expression of VEGF and b-FGFwas 75%,75%,85% (Z2=0.449,P=0.799) and 30%,25%,30% (x~2=0.141,P=0.922),respectively.Statisticalanalysis revealed a positive correlation between the expressionof VEGF and MVD (r=0.552,P<0.001).CONCLUSION:There has been little influence of lipiodolchemoembolization on the formation of tumor angiogenesis,but the development of neovascularization and expression of VEGF play important roles in establishment of collateralcirculation and reconstruction of blood supply of residualcancer tissue. AIM: After transarterial chemoembolization (TACE), theresidual cancer cells are under extensive hypoxic or evenanoxic environment. Hypoxia can lead to adaptive responses. For example, angiogenesis will help these cells survive. Yet study, we examined the effect of TACE on angiogenesis and expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF) and to assesstheir relevance to Walker-256 transplanted hepatoma. METHODS: Male Wistar rats were inoculated with Walker-256 tumor in the left lobe of liver. Angiography and transarterial chemoembolization were performed at d14 aftertransplantation.Sixty rats bearing walker-256 transplantedhepatoma were randomly divided into control group, arterialinfusion group and TACE group. Each group consisted oftwenty rats. Normal saline, 5-Fu, 5-Fu and lipiodol were infused through hepatic artery respectively. Two weeks afterthe infusion, staining of factor Ⅷ, VEGF and b-FGF wasperformed by immunohistochemistry method in routinepar affin-embeded sections. Microvessel density (MVD) was counted in endothelial cells with positive factor VIII. theirexpression levels were analyzed in conjunction with thepathologic features .RESULTS: While a smaller tumor volume was found in TACEgroup (F = 37.818, P <0.001) no statistical differences between MVD and VEGF and b-FGF were found in the 3 groups. MVD of the control group, chemotherapy group and chemoemoblization group was 80.84 ± 24.24, 83.05 ± 20.29 and 85.20 ± 23.91 (F = 0.193, P = 0.873) respectively.The positive expression of VEGF and b-FGFwas 75%, 75%, 85% (Z2 = 0.449, P = 0.799) and 30%, 25%, 30% . Statistical analysis revealed a positive correlation between the expression of VEGF and MVD (r = 0.552, P <0.001) .CONCLUSION: There has been little influence of lipiodolchemoembolization on the formation of tumor angiogenesis, but the development of neovascularization and expression of VEGF play important roles in establishment of collateralcirculation and reconstruc tion of blood supply of residualcancer tissue.