Experimental Study Of The Effects Radiofrequency Ablation Of Transplanted Hepatocellular Carcinoma Brought To Remnant Carcinoma

Objective: To investigate the applicability of modified technique of tumor tissue transplantation in establishing transplanted rabbit hepatocellular carcinoma model and the proliferation, apoptosis and local immune functional change of the remnant carcinoma after radiofrequency ablation of the transplanted hepatocellular carcinoma.Methods: Using tumor tissue suspension to inoculate and establish VX2 tumor-bearing rabbits. Tumors were harvested and cut into small pieces. Then laparotomy was performed on 52 New Zealand white rabbits and small pieces of VX2 tumors were transplanted in their liver lobes. Palpation and MRI scan were utilized to make sure the forming of tumors. Routine pathological and immunohistochemical analysis were done on 5 tumors as control. The remaining 45 tumor-bearing rabbits were then randomized into 3 groups and underwent laparotomic radiofrequency ablation, laparotomic tumor resection or laparotomy without treatment, respectively. MRI was applied to exam the morphological change of the tumor 1, 2, 3 weeks after ablation. Rabbits were then sacrificed and the remnant carcinoma tissue was harvested and went through routine pathological and immunohistochemical analysis on the expression of CD3, CD56, CD68, CD31 and BCL-2. The remnant carcinoma tissue and non-ablated tumor tissue were transplanted subcutaneous on the abdomen in 2 groups, together 10 rabbits respectively. Tumor volume was measured and growth rate calculated on a series of time points to evaluate the proliferation ability of remnant carcinoma.Results: 1. Inoculation of tumor tissue suspension could establish VX2 tumor-bearing rabbits. Transplanted tumor tissue grew on all 52 rabbits. After 3 weeks the tumor could grow to the size that this study required. 2. Immunohistochemical analysis of the remnant carcinoma showed that the group treated with radiofrequency ablation had a significant increase of CD3, CD56 and CD68 positive cells compared with the other two groups. However the microvessel density marked by CD31 and the number of tumor cells expressing BCL-2 dropped dramatically. 3. Inoculated remnant carcinoma tissue could grow and form solid tumors, yet slower than normal carcinoma tissue.Conclusion: 1. With a higher tumor forming rate yet less intraperitoneal implantation, modified technique of tumor tissue transplantation was easy to perform. 2. Radiofrequency ablation could reduce local blood supply and promote apoptosis, therefore slow down the proliferation of tumor cells. 3. Radiofrequency ablation could increase the local immunity of remnant carcinoma, slow down the development of tumor and hold the time for re-treatment.