The World Health Organization's International Agency for Research on Cancer (IARC) has released the latest global cancer burden data for 2020, which shows that 19.3 million new cancer cases happened and nearly 10 million deaths occurred in 2020. Currently, one in five people of the world will have cancer in their lifetime, and one in eight men and one in 11 women will die of cancer. According Taiwan Cancer registry introduction from Ministry of Health and Welfare in 2017, the number of new cancer cases was 111,684, 5,852 more people than in 2015. Liver cancer, in particular, ranks fourth in the cancer rankings. The main causes of liver cancer are hepatitis B, hepatitis C, or cirrhosis of the liver caused by alcohol. Other causes include Aspergillus flavus toxin, non-alcoholic fatty liver disease and liver aspirates etc.

Immune cell therapy is an emerging field in the treatment of advanced liver cancer. Many types of immune effector cells such as lymphokine-activated killer (LAK) cells, dendritic cells (DC), tumor infiltrating lymphocyte (TIL) cells, cytokine-induced killer (CIK) cells, and lymphocyte-activated lymphocyte (LAK) cells are used to treat advanced liver cancer. CIK cells have been developed for immunotherapy applications. CIK cells such as CD3+CD56+ cells, CD3+CD56- cells and CD3-CD56+ cells, have the ability to kill tumors directly by demonstrating the non-restrictive cytolytic effect of MHC, similar to the function of general T cells. CIK cells bind to LFA-1 ligands on tumor cells through LFA-1, resulting in tumor cell killing, and then binding of the receptor to its ligand on NK cells initiates a downstream cell signaling pathway and further activates CIK cells for tumor cytotoxicity. Finally, CIK cells activate the signaling pathway via Fas-FasL and induce apoptosis in cancer cells. DCs are differentiated from hematopoietic stem cells in the bone marrow, often in the form of monocytes, which differentiate into mature dendritic cells in response to cytokine stimulation. After tumor-associated antigen (TAA) phagocytosis, antigens are treated by two pathways, the cytosolic pathway and vacuolar pathway, by which they are processed into peptides and loaded onto the major histocompatibility complex class I(MHC I). Then the TAA-MHC I complex is delivered to the DC surface. When DC-presenting TAAs migrate and reach the lymph nodes, they are able of priming T cells and prompting anti-tumor immunity. Dendritic cells are efficient activators of naïve T cells and are potent APCs. They play a central role in immune-mediated cancer elimination through antigen presentation and T-cell priming. More recently, they have been combined to form DC-CIK cell therapy, which is a combination immunotherapy where DC and CIK cells are cultured together. In terms of therapeutic mechanism, dendritic cells are specialized antigen-presenting cells, and mature dendritic cells can present tumor antigens via the MHC-I pathway to effectively counteract the immune escape mechanism of tumor cells. The specific tumor-killing effect of CIK is further enhanced. Many studies have shown that treating cancer patients with DC-CIK cells significantly prolong the survival time and enhance the immune function of the patient.

Recent trends in cancer treatment have confirmed that when cryoablation of tumors is combined with immune cell therapy, it can have a good complementary effect and significantly improve the efficacy of cancer treatment. It is believed that cryotherapy causes necrosis of tumor cells through the physical changes of osmotic shock produced by repeated freezing and thawing, which in turn releases tumor antigens and activates anti-tumor immune responses. A retrospective study conducted in 2013 in patients with stage IV lung cancer investigated the efficacy of cryoablation combined with immune cell DC-CIK and showed that cryoablation with DC-CIK significantly prolonged the overall survival (OS) of patients. The results of the 2017 clinical trial showed that cryoablation with NK cell therapy improved the clinical response rate and disease control rate (DCR) of patients with advanced lung cancer, with the proportion of patients with PR (63.3% vs. 43.3%, P\<0.01) and disease control rate ( The results of the clinical trial in advanced hepatocellular carcinoma showed that among 61 patients admitted from 2015 to 2017, cryoablation with NK immunotherapy significantly prolonged the progression free survival (PFS) of patients (9.5%). (PFS) (9.1 months vs. 7.6 months, P=0.0107), response rate (60% vs. 46.1%, P\<0.05) and disease control rate (85.7% vs. 69.2%, P\<0.05).

The trial was designed as a single-arm, uncontrolled, open-label, non-random assignment design. The efficacy and safety of hepatic artery infusion with autologous DC-CIK immune cells before and after ablation of liver tumors using cryoablation technique in patients with advanced liver cancer was investigated. The DC-CIK immune cell therapy technology was developed in collaboration with Bohui Biotech, and the core cell technology was transferred from Dr. Hasumi autologous immune cell therapy in Japan. The program will track the changes in tumor size and tumor index before and after treatment, and conduct safety assessment to evaluate the safety and efficacy of this trial treatment.

During the clinical trial, peripheral blood will be collected from patients for exploratory index analysis to complement the clinical evaluation results. According to the results of the clinical study in 2013, patients with stage IV solid cancer who had failed standard treatment had increased CD8+CD56+ cell populations after autologous immune cell therapy by Dr. Hasumi in Japan and continued to be followed up until one year later. In 2019, a study also showed that disease control was lower in the group of patients with liver cancer with high free DNA concentrations treated with sorafenib than in the group with low free DNA concentrations. The whole-genome sequencing of cell-free DNA (cfDNA) to obtain copy number alteration (CNA) profiles can be used as predictors of sorafenib treatment outcome. Therefore, in this clinical trial, blood samples were taken from patients before and after treatment, and the distribution of immune cell populations and changes in cell-free DNA (cfDNA) in blood were analyzed separately by separating the buffy coat and plasma using a density gradient centrifuge, and using the Qubit 2.0 Fluorometer. The qubit dsDNA High Sensitivity assay kit (Life Technology, Carlsbad, CA, USA) was used to quantify the amount of free DNA and to detect the copy number of free DNA, and to analyze the free DNA to find out the biomarkers that can be used for treatment effect tracking.