Two therapies to treat cancer: target therapy, immunotherapy
2020-06-24
As humans accumulate more and more medical knowledge, cancer treatment methods have also continued to progress, and a variety of different treatment methods have been gradually developed. The specialist will first comprehensively evaluate the patient's cancer type, severity and physical condition, and then formulate the most beneficial treatment for the patient. In recent years, cancer "targeted therapy" and "immunotherapy" have received high attention. However, the charges for these two therapies are relatively expensive. Why?
What is "targeted therapy"? How does it fight cancer cells?
Targeted therapy is a new drug developed for the physiological and biochemical characteristics of cancer. This drug is aimed at the cause of cancer cell generation. It is very focused on inhibiting or destroying the important mechanisms required for cancer cell survival. Just like archery, drugs The bow and arrow are shot very accurately at the center of the target.
But not all cancer patients are suitable for targeted therapy. Target therapy may be limited to patients whose tumor site has an appropriate target to allow a certain target therapeutic drug to function. Sometimes, a patient is suitable for targeted therapy only if the patient meets certain conditions (for example, the cancer has not responded to other therapies, the cancer has spread, or it cannot be surgically removed).
Basically, target drugs can be divided into two categories, one is the so-called protein kinase inhibitor, we can think of it as a small elf-oriented missile, because of its small molecular weight, it can flexibly attack and suppress cancer cells It is used orally and has been widely used to fight cancers such as leukemia, breast cancer, lung cancer, liver cancer and renal cell cancer.
Compared with protein kinase inhibitors, another type of monoclonal antibody target drug is a huge weapon like an intercontinental missile. It has a huge molecular weight and can directly attack the target of cancer cells in a way that the antibody fights. Only by intravenous injection can the effect be achieved. Dozens of drugs are currently available for use in the market. In breast cancer, hypopharyngeal cancer, lymphoma and colorectal cancer, there are such targeted drugs that can be administered.
Because the target drug is convenient to take, it has little effect on the bone marrow hematopoietic cells and the immune system, and the side effects are generally less than traditional chemotherapy drugs. Therefore, more and more people adopt this treatment method because of the development of the target drug for cancer. Basically it takes more than ten years, more than 20 years, plus patent rights, research and development, promotion and other costs, the price is relatively high.
What is "immunotherapy"? How does it treat cancer?
Immunotherapy is the latest anti-cancer therapy in recent years. Its operating principle is different from traditional chemotherapy and target drugs. It stimulates the body's immune system, wakes up T lymphocytes in the body to kill cancer cells, and strengthens its ability to identify cancer cells. Cancer cells can no longer avoid the attack of the immune system. Immunotherapy is currently only used for a small number of cancers, and the drug cost is very expensive.
The most famous example is the former US President Jimmy Carter. After receiving chemotherapy and immunotherapy, he announced in 2015 that the melanoma tumor that had metastasized to the brain disappeared. The drug used by Carter is a "monoclonal antibody drug" that can strengthen the immune response. This is because some proteins on the immune cells (called "immune checkpoints") will "suppress" the activation of immune cells. Through this drug, you can prevent the suppression reaction and restore the immune cells' ability to attack cancer cells.
At present, immunotherapy can be roughly divided into three types: "vaccine", "single antibody drug" and "cell therapy":
Vaccines: Proteins are used to synthesize specific tumor antigens, or are made from fragments of cancer cells in patients, used to treat rather than prevent cancer. After being injected into the body, the patient is induced to produce an immune response, which in turn produces antibodies against such tumors.
Monoclonal antibody drugs: including two kinds of target drugs and "immune checkpoint inhibitors" that have been relatively well known in recent years, both are artificially made into monoclonal antibody drugs. The former is taken orally, and when combined with specific cancer cells, it starts the immune system to attack. The latter injects different doses according to the patient's body weight, which can prevent the immune cells from suppressing the reaction and make the immune cells unable to activate.
Cell therapy: remove the patient's blood and stimulate, culture, activate or modify the patient's autoimmune cells in vitro, such as natural killer cells (also known as NK cells), dendritic cells (also known as DC cells) or toxin-killing T cells Wait, and then return to the patient's body to increase the ability of the immune system to poison cancer cells.
