Types Of Chemotherapy
There are many types of drug treatment for cancer patients, such as chemotherapy, targeted therapy, immunotherapy and hormone therapy.
Targeted Therapy: Monoclonal Antibodies, Anti-Angiogenesis And Other Agents
Targeted therapy is the result of almost 100 years of research on the differentiation of cancer and normal cells. At present, cancer therapy is aimed directly at destroying rapidly dividing cancer cells, as one of the characteristics of cancer cells is rapid division. Unfortunately, some normal cells also divide rapidly, which leads to a number of side effects. The point of targeted therapy is to identify other properties of cancer cells. Scientists look for differences between cancer cells and normal cells. This information is used to create targeted therapies and attack cancer cells without harming healthy cells, resulting in fewer side effects. Current targeted therapies include the use of monoclonal antibodies and anti-angiogenesis drugs.
A number of targeted therapies target the internal components and functions of cancer cells - using small molecules that can penetrate the cells and disrupt their function, thereby causing their destruction. There are several types of targeted therapy that target the inside of the cell. Other targeted therapies target receptors on the outside of the cells, also known as monoclonal antibodies. Anti-angiogenesis drugs target the blood vessels that supply the cells with oxygen, which eventually starves the cells.
Researchers agree that targeted therapies do not replace traditional treatments. Targeted therapy involves the production of components such as monoclonal antibodies or anti-angiogenesis drugs, which should be used in combination with traditional treatments in the short term.
Monoclonal Antibodies
Monoclonal antibodies are a relatively new type of 'targeted' cancer therapy. Antibodies are part of the immune system. The body normally produces antibodies in response to an antigen (such as a foreign protein) being introduced into the body. The antibodies bind to the antigen to mark it for destruction by the body's immune system. With this technology, the treatment can target individual cells, which reduces the toxicity to healthy cells.
Monoclonal antibody therapy can only be carried out if the cancer antigen (and the corresponding antibodies) have been identified. The monoclonal antibodies are listed below:
- Alemtuzumab
- Gemtuzumab ozogamicin
- Rituximab
- Trastuzumab
- Ibritumomab thioxetan
- Others
Anti-Angiogenesis (Angiogenesis Inhibitors)
Anti-angiogenesis is the process of preventing new blood vessels from forming.
In normal tissue, new blood vessels form during tissue growth and repair (e.g. wound healing) and during pregnancy and child development. Blood vessels carry oxygen and nutrients needed for growth and survival.
In the case of cancer, the tumor needs the blood vessels to grow and spread. Through complex processes, the endothelial cells lining the inside of the blood vessels divide, grow and create new blood vessels. This process is called angiogenesis, and it occurs in both healthy and cancerous tissue.
Substances are known to stimulate angiogenesis and also to stop or inhibit it. Since 1971 the Massachusetts surgeon Judah Folkman has been researching these substances. According to his theory, if a possible tumor is prevented from growing and spreading, it will eventually die of "starvation". On this basis, scientists are studying the production of both natural and synthetic substances called anti-angiogenic agents or angiogenesis inhibitors. In animal studies, these angiogenesis inhibitors have been successful in stopping new blood vessels from forming, thus starving and killing cancer.
It is too early to say how effective these angiogenesis inhibitors will be in the treatment of cancer in humans. More than twenty substances are currently in clinical trials for various types of cancer. Some of these angiogenesis inhibitors are commercially available and approved by the FDA for other purposes. Drugs such as interferon-alpha and thalidomide are thought to inhibit angiogenesis to some extent and are being studied in some cancers. Other drugs against angiogenesis are new and not FDA-approved and can only be used in clinical trials, and in most cases in the later stages of the disease. It is hoped that angiogenesis inhibitors will have less toxicity, as they only affect the formation of new blood vessels.
Long-Term And Short-Term Side-Effects Of Chemotherapy
Like most other medicines, chemotherapy drugs have side effects. Side effects of chemotherapy are adverse events that occur as a direct result of taking the medicine. A side effect of a medicine can easily be mistaken for a cancer symptom.
Different drugs have different side effects, but not all chemotherapy drugs cause side effects. In general, chemotherapy damages the cells that divide, so it can damage the parts of the body where healthy cells divide frequently. The mucous membrane of the mouth, intestines, skin, hair and bone marrow are often damaged by chemotherapy. Chemotherapy may cause problems such as feeling tired and weak, nausea, vomiting, hair loss, etc.
However, side effects do not occur in all patients. A patient may not experience any of the side effects of chemotherapy or may experience some or all of them. The presence of specific side effects, their occurrence or cessation and their severity depend on many factors - how long the patient has been taking the medicine, the general health of the patient, the dose or quantity of the medicine, the way the medicine is taken, other medicines taken in combination, etc.
Important issues related to short-term and long-term side effects of chemotherapy:
- A number of side effects of chemotherapy are serious conditions that require treatment.
- A number of side effects cause anxiety and irritation.
- The patient's side effects should be discussed with the doctor treating them.
- If the patient suffers a side effect, he or she should contact the doctor or center where the treatment is being given.
- Most side effects do not cause long-term damage and gradually disappear when the treatment is finished.
- If your patient does not have any side effects, this does not mean that the treatment is ineffective.
- There are only a few long-term side effects of chemotherapy, all others are short-term.
Side effects of chemotherapy can be unpleasant, but it helps the patient to try to see the problems related to the benefit of the treatment. It is important to note that chemotherapy does not cause side effects in all cases - every patient has a different reaction. Almost all side effects are temporary. They will gradually disappear when the treatment is stopped.
