Octreotide augments the effects of hepatic arterial occlusion in treating a rat liver tumor model.

Background/aims: To observe if octreotide can augment the effects of hepatic arterial occlusion for transplanted cancer in rat's liver.

Methodology: Walker 256 carcinosarcoma was transplanted into rat's liver to create the liver cancer model. Hepatic arterial ligation was used to block the hepatic arterial blood supply. Rats bearing tumor were divided into three groups: control group, HAL (hepatic arterial ligation) group, and HAL plus octreotide group. Change of tumor volume and tumor growth inhibiting rate after therapy were evaluated. Hoechst 33342 labeling assay was used to analyze the blood perfusion of tumor (the labeled cells' number presenting blood perfusion). Expression of vascular endothelial growth factor and matrix metalloproteinase-1 mRNA was detected by in situ hybridization, and the level of serum vascular endothelial growth factor was assayed by ELISA.

Results: Six days after hepatic arterial ligation, the mean tumor volume in control group, HAL group, and HAL plus octreotide group was 0.103 +/- 0.043 cm3, 0.030 +/- 0.018 cm3, and 0.016 +/- 0.005 cm3, respectively. The tumor volume in the two behind groups was smaller than that in the control group (P < 0.01), and the tumor growth-inhibiting rate was 70.8%, and 84.5%, respectively. Compared with the HAL group, the tumor volume in HAL plus octreotide group decreased significantly (P < 0.05). Hoechst 33342 labeled cells' number in control group, HAL group, and HAL plus octreotide group was 369.7 +/- 30.2, 344.1 +/- 26.0, and 323.2 +/- 40.4, respectively. The number in HAL combined with octreotide group decreased significantly compared with that in control group (P < 0.05), which suggested that the blood perfusion of tumor in HAL plus octreotide group decreased significantly. The expression of vascular endothelial growth factor and matrix metalloprotenase-1 mRNA decreased slightly, but not significantly in HAL plus octreotide group compared with that in HAL group (P > 0.05).

Conclusions: The results suggest that octreotide can promote the effects of hepatic arterial occlusion therapy for transplanted cancer in rat's liver. Decreasing the blood perfusion of tumor after hepatic arterial blockage maybe one of its major mechanisms.