To answer the above questions, we must first know, why do people produce antibodies?
In the long process of evolution, the human body has formed a complete defense network-the immune system. Non-self substances, senescent/dead cells, cancerous cells, etc. from outside the body will be recognized by the immune system in the body. Such substances are called antigens. Antigens stimulate the immune system to produce corresponding antibodies. The antibodies bind precisely to the antigens (like a key and lock), and then activate the body’s immune system. The activated immune cells will eliminate these non-self substances, senescent, dead cells and some cancerous cells.
The key to whether or not antibodies can be produced after cancer is: whether cancer cells contain antigens that can be recognized by the immune system.
Cancer cells can evade immune system surveillance and attack
Unfortunately, cancer cells are derived from the body’s own cells, and most of the components are similar to normal cells. Although cancer cells also express some new antigens on their surface that normal cells do not have, and most of them can be recognized and killed by the immune system, a small number of “cunning” cancer cells will continue to modify their own antigens or change the environment around the cells. Evasion of the immune system’s surveillance and attacks causes the immune system to lose control of the growth of cancer cells. It is like criminals constantly changing their appearance and forging identity information in order to avoid police arrest. This is the immune escape mechanism of tumors. Therefore, even if you have had cancer, due to the immune escape mechanism of cancer cells, even if the body produces corresponding antibodies, it is not enough to cope with the “crazy growth” of tumors. In addition, the original antibody can only match the primary tumor, and cannot achieve the purpose of preventing the body from suffering from secondary cancer.
Someone may ask: Since the immune escape mechanism helps tumor growth, why can the HPV vaccine, which has been popular in recent years, help prevent cervical cancer?
This is because the cervical cancer vaccine is not against cancer cells, but against the virus that causes cervical cancer-HPV (Human Papilloma Virus). Data show that 99.7% of cervical cancer patients can detect HPV infection, among which the most common high-risk types are HPV16 and HPV18. More than 90% of cervical cancers in China are related to persistent infection of these two high-risk HPV types. Human immunity to HPV is generally not strong, and cannot produce large amounts of antibodies in a timely manner like a viral cold, which leads to long-term survival of HPV and causes cervical cancer. The HPV vaccine is to inject particles with HPV antigen characteristics into the human body to induce the immune system to recognize them and produce antibodies to eliminate the virus and reduce the incidence of cervical cancer. It does not allow the body to directly produce antibodies that destroy cancer cells.
4 tricks to “block” the “loophole” in the escape of cancer cells
After clarifying the immune escape mechanism of tumors, let’s talk about how to plug this “hole”.
1. Immunotherapy – blocking passage of cancer cells escape
treatment principle is more complex than immune HPV vaccine, which is to restore the body’s normal immune response to the cancer cells by the drug, a method to control and tumor clearance. For example, PD-1/PD-L1 inhibitors are currently the most researched in medicine.
Studies have found that cancer cells can produce a protein called PD-L1, and there is a protein called PD-1 on the surface of immune cells. These two proteins can bind to each other, but this combination does not allow immune cells to destroy cancer cells. On the contrary, after they are combined, the killing function of immune cells will be inhibited. It is equivalent to covering the immune system with a thick veil, turning a blind eye to the cancer cells passing by, allowing the cancer cells to successfully achieve immune escape.
After being imported into the body, immune drugs can accurately bind to the proteins on the surface of cancer cells. In this way, the proteins on the surface of cancer cells and immune cells will not bind to each other, and the killing function of immune cells will not be inhibited, and the immune system will be able to Normal work, then the body can achieve anti-cancer effects by producing antibodies.
2. targeted therapy – synthetic antibodies destroy cancer cells
since the body lacks the ability to produce large amounts of anti-cancer antibodies, if developed specific antibodies with anticancer properties, can be anti-tumor antibodies by entering it?
The answer is yes. This type of antibody is an antibody synthesized by scientific researchers that can destroy cancer cells. After entering the body, it can accurately bind to cancer cells to achieve the purpose of killing cancer cells. For example, rituximab for the treatment of non-Hodgkin’s lymphoma, trastuzumab for the treatment of breast cancer, and cetuximab for the treatment of colorectal cancer have been widely used in clinical practice. They are mainly combined with an already clear carcinogenic site (the site can be a protein molecule inside a tumor cell, or a gene fragment), which directly leads to cancer cell apoptosis, similar to a missile’s precision strike, and an archery hits the target. , Does not rely on the immune system.
3. Immune cell therapy-transforming immune cells that multiply and recognize cancer cells
In addition, since the proportion of autoimmune cells that can recognize cancer cells is very small, researchers try to extract immune cells from the patient’s blood. Through special modifications, they can recognize antigens on the surface of cancer cells. The cells undergo large-scale expansion, and finally the modified immune cells are returned to the human body. While the immune cells play a role, they will continue to reproduce themselves, so as to achieve the goal of lasting and precise killing of tumors. This is the immune cell therapy that has achieved preliminary results.
4. immune system modulating agents – anti-tumor immune activation
BCG treatment of bladder cancer, thymopentin and the like are also inhibit cancer by activating the immune system to achieve the antitumor effect, the immune system modulator is called. However, the anti-cancer effect of immune system modulators alone is very weak, and it is necessary to go to specialized hospitals to listen to the opinions of specialists for comprehensive and systematic anti-cancer treatment.
Cancer is a systemic disease, regular follow-up is very important
After having cancer, it is more important to follow-up after treatment than to entangle whether it will produce antibodies.
Although some patients can achieve clinical cure after surgery or various treatments, cancer is a chronic and complex systemic disease, and some patients will still relapse or even metastasize after treatment; or some patients have been diagnosed when the tumor is in the middle. In the late stage, even if the treatment achieves better results, the remaining cancer cells in the body will re-proliferate when the treatment is stopped or the body’s immunity decreases. Therefore, regular follow-up is very important. First, it can help cancer patients find and treat early again, without missing the best time for treatment; second, it can help bring patients psychological support and comfort; third, it can adjust the treatment plan such as medication and inspection in time.
Depending on the type of cancer, the time and content of the follow-up are also different. Specific influencing factors include the stage of the cancer, the degree of malignancy of the tumor, whether it is operated, whether there is lymph node metastasis, whether there is metastasis to other parts, and the course of treatment. In principle, most cancer patients need to be reviewed once every 3 months within 1 year after the end of treatment; within 2 to 4 years after the end of treatment, they need to consult an oncologist based on their own conditions, and make a reasonable follow-up plan based on their own conditions and doctors’ experience ; For more than 5 years, it needs to be reviewed once every six months to one year.
In the early or middle and late stages, when there is a change in health, return to the hospital as soon as possible and report to the doctor in time. Allowing doctors to judge whether these problems are related to cancer and intervene in time is the key to prolonging survival and ultimately “cure”.