Immunotherapy for cancer treatment: side effects and how it differs from Chemotherapy
Immunotherapy is a relatively new method of treating cancer that involves using the body’s immune system to fight cancerous cells. Immunotherapy can help by boosting the immune system to be more effective in fighting cancer, or by marking cancerous cells, and making it easy for the immune system to identify them.
How does Immunotherapy work?
The immune system comprises cells and special organs that protect the body from harmful viruses and infections. The immune system is aware of all the minute elements that exist in the body and attacks any foreign particle introduced in the body.
Germs and viruses contain specific proteins that the immune system does not recognize, and hence it attacks these germs. Against cancer cells, however, the immune system is less successful.
Cancerous cells are normal cells that have mutated. The immune system has a hard time differentiating between healthy cells and cancer cells. Even if the cancer cells are correctly identified, sometimes the immune response is not enough to make the body healthy.
In such cases, immunotherapy for cancer is a big help in boosting the immune system and helping it in differentiating between normal, healthy cells and cancer cells.
Different types of Immunotherapy
Immunotherapy has a more positive outcome on some types of cancers than others. Different ways of applying immunotherapy are considered for different types of cancers.
The types of immunotherapy for cancer are:
1. Immune checkpoint inhibitors
The immune system has checkpoints that make them able to identify between healthy cells and any foreign particles. Since cancer cells are mutated cells, they are many times able to bypass these checkpoints and spread.
Immune checkpoint inhibitors are drugs that manipulate the checkpoints in the immune system and make them target the cancer cells. Medications for checkpoint inhibitors don’t attack the cancerous tumours. Instead, they boost the immune system to fight cancer cells more effectively.
2. Cancer vaccines
Vaccines introduce a weak or dead virus into the body, which makes the immune system fight against foreign particles. The immune system has a memory—once it defeats the bad cells, it remembers and protects the body against any future infections.
Cancer vaccines aim to induce the immune system to attack cancer cells. Some vaccines could potentially prevent certain cancers from occurring.
3. Adoptive cell therapy
Adoptive Cell Therapy uses the cells of the patients to fight against diseases. T-cells are the backbone of the immune system. These cells direct the immune system to the affected areas and trigger an immune response in fighting infections and viruses. CAR T-cell therapy involves extracting a few T-cells from the body and genetically altering it with a disarmed virus, and re-injecting them into the body.
These altered cells are known as ‘a living drug’ as once they enter the human body, they multiply as other cells do. The modifications of the cells can help the immune system to identify and fight against the cancer cells and hopefully eliminate cancer.
The success rate of Immunotherapy
Unlike other forms of treatments, immunotherapy for cancer helps towards arming the body for long-term survival. As the treatment is directed at the immune system, the modifications can be maintained even after the treatments stop.
Doctors observe a patient who has completed treatment for cancer. The chance for relapse is high in the first five years. However, various studies have identified that in most cases, immunotherapy for cancer has prolonged the five-year survival period by a few more years. However, each case is different, and the survival rate depends on many various factors.
Side effects of Immunotherapy
Immunotherapy for cancer is not without side effects. This treatment makes changes to the body on a cellular level. The base protection system of the body gets modified to fight against the cancerous cells. Although all the treatment types aim at only targeting the mutated cancer cells, it is still possible for the immune system to start attacking the healthy cells in the body. Palliative care is initiated along with the procedure to help improve the quality of life during and after cancer treatment.
Most common side effects of immunotherapy include,
- Skin irritations
- Symptoms similar to flu
- Water retention
- Hormonal changes
- Muscle aches
- Shortness of breath
Depending on the intensity of the side effects, the treatments are either stopped or modified. Your doctor may prescribe drugs to combat the side effects once the treatment is resumed.
Difference between Immunotherapy and Chemotherapy?
Chemotherapy is one of the more well-known treatments available for treating cancer. Initially, chemotherapy used to be the only treatment available against cancer, but over the years, many new options like cancer immunotherapy have become available.
- Chemotherapy uses drugs in combination with radiation to kill cancer cells directly. Cancer Immunotherapy directs the patients’ own immune system to combat the cancer cells.
- Chemotherapy attacks the cells in the body directly, and this includes both cancerous cells and non-cancerous, healthy cells. In immunotherapy, the cells in the immune system are modified to seek out and attack the cancerous cells.
- Treating with chemotherapy shows a visible change in the cancerous growth immediately. In contrast, the effects of immunotherapy are not immediate and are seen more gradually.
- Nausea, mouth sores, and hair loss are a few well-known side effects of chemotherapy. The side effects of immunotherapy are those that generally occur due to a weak immune system like cold, fatigues, and others.
Treatments for cancer are chosen depending on several factors. Choosing immunotherapy for cancer over chemotherapy or any other treatment depends on the type of cancer, at which stage the cancer is in, any other treatments undergone for cancer, and the overall health of the patient. Besides, cancer immunotherapy can be used in multiple ways to help the immune system fight against the disease.
Any cancer treatment is taxing on the body, and palliative care must be included right from the start to manage any side effects as and when they are detected.