Pilot Study Of Immune Function Change After Ultrasound-guided Radiofrequency Ablation For Liver Cancer

Liver cancer is one of the most common malignant tumors in the world. In clinic, primary treatment of liver cancer is surgery resection, but the resectability rate of it is only about 20-30%. Thus non-surgical treatments have been the focus of research in this field. In recent years, with the improvements of ultrasound technique and radiofrequency instruments, ultrasound guided radiofrequency ablation (RFA) has been greatly developed as an interventional treatment. Now, the overseas researches showed RFA can produce good treatment results for tumors smaller than 5cm in diameter with multiple needle electrodes, and it can even cause complete necrosis for those smaller than 3 cm in one time, better than percutaneous ethanol injection treatment (PEIT) in effects and indicationsBesides the treatment for liver cancer, the effects of RFA in other aspects of the body are not very clear. The immune function of patient with malignant tumors is always low and turbulent. The cytokine of tumor cells can cause immune inhibition of the tumor host. Metastasis and recurrence have something to do with the inability of immune. Though the patient was released from the tumor by the routine resection, theimmune system was stricken at the same time. TAE can control the liver cancer well but it inhibited the immune function greatly and deteriorated the patient's body. So this is bad for decreasing the recurrence rate of liver cancer. While there were some researches indicated that localized microwave thermal treatment could improve the immune function of the body, decrease the rate of recurrence and metastasis. As one kind of localized thermal treatments, the effect on the body immune function has been a hot focus of the researches around the world. In the body immune system, cell immune induced by T cell is the main antitumor immune, NK cell can kill the tumor cell directly and TGF- β₁ has been related with the mechanism of tumor growth. Some researches show that liver cancer can excrete lots of TGF— β₁, which inhibited the growth of normal liver cell around, because of maladjustment of negative feedback.Recent reports show that the serum level of NK cell and CD4+ are low, CD8+ and TGF- P \ are high in patients with cancer. Some domestic researchers found that serum level of CD4+ and ratio of CD4+/CD8+ increased and sIL2-R decreased greatly 3 weeks after RFA. Wang qing et al, had done a similar research and found serum level of CD3+, CD4+, CD8+ and ratio of CD4+/CD8+ had no obvious changes at 3 days after RFA, but at 7 and 14 days after RFA, the level of CD3+.CD4+ and ratio of CD4+/CD8+ increased greatly. These results indicated the patient's immune function was improved. But they were all changes in short term, no reports followed the changes of T cell for longer time after RFA, and no reports about the changes of NK cell and TGF- β₁ .In this study, the serum level of CD4+, CD8+, CD3+, NK, TGF-β₁ and ratio of CD4+/CD8+ after RFA were compared with those before RFA to discuss the effect of RFA on the cell immune function.Material and methods1. Research objectsFrom Jun. 2004 to Jan. 2005, 20 patients (16 men, 4 women) with unresectable liver cancer (confirmed by pathology of surgery or biopsy) were chosed in our hospital. There were 15 hepatolcellular carcinoma and 5 metastsis. Patient age range from 34 to 76 years (median age is 55). Enrolling conditions: the diameter of tumor is smaller than 5 cm, the number of tumors is less than 6, the patient has no tumor embolisms of portal vein or IVC, without metastasis out of liver, The liver function grade should be Child A or Child B, the blood platelet counts >5 X 10⁹/L, PT <18 seconds. All the patients accept RFA by free will, and do not take other treatments in one month after RFA.2. Ultrasound guided RFAThe way of RFA was design by the volume of tumor, using RITA1500 and WE7568 radiorequency generator.3. Evaluation of CD4+, CD8+, CD3+, NK cellAll the patients' blood (2ml) were adopted to evaluate the level of CD3+, CD4+, CD8+, NK respectively in 1 day before RFA, 14 and 28 da...