1.Tumor vaccine therapy Tumor vaccine immunotherapy refers to the use of tumor or tumor antigen substances to induce specific cellular and humoral immune responses in the body, enhance the body’s anti-tumor ability, and stop the growth and spread of tumor and recurrence. A large number of clinical studies on tumor vaccines have been conducted or are ongoing. Hooer et al. randomly divided 99 colorectal cancer patients into ASI treatment group and control group, and the ASI group started tumor vaccine injections at 3-4 weeks after surgery, the first two with a mixture of radiation-treated autologous tumor cells and BCG, and the third with tumor cells alone. The results showed that effective immunization could improve tumor-free survival and overall survival of patients. Effective immunization was defined as the formation of sclerotic nodules at the local injection site after the 3rd tumor vaccine injection due to delayed hypersensitivity reaction. The statistical results also suggest that the larger the diameter of the nodules formed, the better the prognosis. 2. Relay cell immunotherapy Relay immunotherapy is to take the donor lymphocytes which have immunity to tumor and transfuse them to the tumor patient, or to take the patient’s own immune cells which are activated and proliferated in vitro and then transferred into the patient, so that they can play the role of tumor in the patient’s body. The effector cells of successive immunotherapy are heterogeneous, such as CTL, NK cells, macrophages, lymphokine-activated killer cells and tumor-infiltrating lymphocytes all play a role in killing tumor cells. Rosenberg et al. treated 30 patients with colorectal cancer with LAK cells + IL-2, a complete anti-tumor immune response was observed in one case and a partial anti-tumor immune response was observed in four cases Cai et al. used DC-CIK cells to treat colon cancer. 491 patients with pathologically confirmed colon cancer were studied, divided into group A: immunotherapy + chemotherapy group, 224 cases; group B: chemotherapy group, 267 cases. one-year survival rate was 93% in group A and 84% in group B (P < 0.05). two-year survival rate was 76% in group A and 69% in group B (P < 0.05). three-year survival rate in group A and 69% in group B (P < 0.05). The three-year survival rate was 80% in group A and 61% in group B. The study confirmed that DC-CIK combined with chemotherapy can benefit the survival of patients and the disease-free survival rate will be improved. 3, monoclonal antibody therapy The use of highly specific monoclonal antibodies as a carrier to bring cytotoxic killing molecules to the tumor lesion, can specifically kill tumor cells. Monoclonal antibodies can exert their killing effects on tumor cells through mechanisms such as induction of apoptosis, complement-dependent cytolysis, and antibody-dependent cytotoxicity. 2014 ASCO meeting reported a chimeric monoclonal antibody for progressive pancreatic and colorectal cancer in a phase I clinical trial, the main study objective was to evaluate the safety of NEO-102 and explore the safe dose of NEO-102 treatment. Nineteen patients were enrolled in the trial and five of the eight evaluable patients achieved SD with overall survival >12 months, three of the five patients had colorectal cancer, two had pancreatic cancer, and three had PD. 12 of the patients were evaluated for toxic reactions and no serious adverse events occurred. The main adverse reactions were third degree diarrhea and anemia. 4.Other immunotherapy Other immunotherapy includes the application of some immunomodulators to activate the anti-tumor immune response of the body by non-specifically enhancing the immune function of the body for the purpose of tumor treatment. Such as BCG, IL-2, levamisole, diphtheria toxoid, OK432, etc. Smith et al. compared patients with colon adenocarcinoma treated by surgery plus BCG with those treated by surgery alone in a 10-year follow-up, and the study showed that although the group treated with BCG could not prevent tumor recurrence, it could prolong the overall survival of patients. brivio et al. took 50 patients with Duke, S classification of D colon cancer. divided into IL-2 treatment group and control group, and both groups were treated with surgery and postoperative 5-FU chemotherapy. The results showed that patients in the IL-2-treated group had higher T lymphocytes, NK cells, and AL cells than those in the control group, and the 1-year survival rate was significantly higher in the IL-2-treated group than in the control group. the IL-2-treated group could counteract the decrease in IL-12 levels and the increase in vascular endothelial growth factor levels caused by surgery, thus eliminating the effect of tumor angiogenesis caused by surgical stimulation. Levamisole has low toxicity and stimulates immune responses by enhancing the function of T lymphocytes, macrophages and neutrophils.