The Effect Of Radiofrequency Ablation With Arsenious Acid On Liver VX2 Tumors And Its Malignant Potency In Rabbits

Objectives:To evaluate the effect of combining radiofrequencyablation(RFA) with arsenious acid(AA) locally treating liver VX2 tumor inrabbits, and to investigate the effect on malignant potency includingProliferating cell nuclear antigen(PCNA),Microvessel density(MVD) andvascular endothelial growth factor (VEGF). Methods: Sixty New Zealand White rabbits with implanted liver VX2tumors were randomly divided into four groups, a control(Isotonicsaline )group(n = 15), an AA group (n = 15) ,an RFA group (n = 15) , and acombination(RFA+AA) group (n = 15). In the RFA and combinationgroups, RFA was performed by laparotomy on VX2 tumors with an outsidediameter of 1.1 mm and a 10-mm-long active electrode at the sameapplication site. Treatment was performed with an energy output of 20 Wand an application time of 4 minutes. Isotonic saline and arsenious acidwere delivered by an infusion pump through openings in the tip of theneedle into the coagulation zone at the rate of 40 mL/h .ALT was detectedbefore the treatment and on the same day, day 3, week 1, 2 after thetreatment. Ultrasoni (US) examination was performed at the same time.Seven rabbits in each group were killed then the tumor inhibitory rate wasassessed 14 days after the treatment.The morphological changes of thetumor and hepatic tissue were also investigated under light microscope.Proliferating cell nuclear antigen(PCNA),Microvessel density(MVD) andvascular endothelial growth factor (VEGF) expression were examined byimmunohistochemistry. The rest rabbits in each group were used to assesssurvival time. Results: 1. Combining (RAF+AA) therapy can increase the volume of necrosisinduced by RFA,and can make coagulation complete. Calcification andfibration can be seen in the area of coagulation necrosis. Embolism oftenappeared near the necrosis. There were chronic inflammation in theperiphery of the coagulation.Mild bile duct proliferations and massproliferating liver cells were observed 14 days after treatment. 2.Combining (RAF+AA) therapy can cause a transient damage to the liverfuncution of the rabbits ,but the level of ALT was in the normalrange(30-110 millImolecular /gram). The level of ALT in the control grouprised step by step.3. The average volume of tumors in the combinationgroup lower than the other groups (P<0.05).The average volume of tumorsin the RFA group was lower than the AA group(P<0.05). 4. The survivaltime of the rabbits in the Combination group was obviously longer than theother groups(P<0.05),for the p value less than 0.05 was considered asstatistically significant. The rabbits in the AA group lived longerobviously,but no statistically significant. Compared with the AA group, theRAF group had longer survival rate(P<0.05). 5. The recurrence rate in theCombination group was lower than the other groups(P<0.05). In the controlgroup, the metastasis rate in the Combination group was 100% which was29.2%.Most metastasis tumors were seen in the lungs,livers and lymphnodes. 6. The PCNA LI in combination group was lowest of the 4groups,and had statistic difference from other groups (p<0.05) . The PCNALI in the RFA group was lower than that of the AA group (p<0.05). 7.TheMVD in combination group was statistically smaller(.05) than the othergroups. The MVD in the RFA group was smaller than that of the AA group(p<0.05) .8. The expression of VEGF protein was statistically lowest(p<0.05) of the 4 groups. The expression of VEGF protein in the RFAgroup was lower than that of the AA group (p<0.05). Conclusions: 1. Combining (RAF+AA) therapy caused transient damage to theliver funcution of the rabbits. 2. Combining (RAF+AA) therapy decresed the volume of liver VX2tumors. 3. Combining (RAF+AA) therapy prolonged the survival time of therabbits. 4. Combining (RAF+AA) therapy decreased recurrence and metastasisof the VX2 tumor. 5. Combining (RAF+AA) therapy reduced proliferation of the VX2tumor cells. 6. Combining (RAF+AA) therapy inhibited angiogenesis of the liverVX2 tumors ,and reduced microvessel density of the VX2 carcinoma. 7. Combining (RAF+AA) therap...