Improving the future prospects of cancer patients is contingent upon conducting research on cancer treatment. The treatments for cancer have become more and more individualized based on the specific characteristics of the cancer due to advancements in treatment and new innovative diagnostic technologies.
Immunotherapy is one such line of treatment that has shown great promise in the 21st century and has gained recognition as the 4th modality of cancer. Immunotherapy primarily focuses on strengthening the immune system and its responses to recognize and attack cancer cells.
The main function of the immune system is to identify any aberrant cells and eliminate them. It can also stop any malignant cells from growing and spreading into other parts of the body.
Despite the immune system’s inherent ability to tackle and get rid of any harmful pathogens, cancer cells often evade the immune system’s responses. They do so by –
- Possessing genetic alterations that obscure their appearance to the immune system and its responses.
- Displaying proteins on their surface that inhibit immune system activity.
- Modifying the healthy cells surrounding the tumor and obstructing their ability to interact with the malignant development.
Cancer immunotherapy aims to overcome the mechanisms tumors use to evade and suppress the immune responses. This resets the immune system’s protective balance and enhances or restores its capacity to identify and eliminate cancer cells from the body.
The adaptive immune system has features of specificity and long term memory which can aid in producing long lasting responses. Increasing the frequency of tumor specific T- cells has been the primary aim and approach of immunotherapy, thereby boosting the immune system and its responses and ultimately identifying and attacking cancer cells in the body.
Immunotherapy Side Effects
Immunotherapy treats a wide range of cancer effectively but like any other line of treatment, immunotherapy drugs are powerful medications that can cause changes within the body. These changes or side effects vary for patients and depend on several factors.
These side effects depend on the type of immunotherapy a patient receives, the type of cancer, its location and a patient’s overall health. Immunotherapy can also cause the immune system to attack the healthy cells of the body which can then result in immune related adverse effects.
Before treatment patients should consult their oncologists to get a better understanding of these side effects and the potential risks associated with immunotherapy. Since immunotherapy primarily boosts the immune system and its responses, it usually doesn’t pose extreme side effects in comparison to other lines of treatment. However, this doesn’t mean that there are no side effects and some of the side effects include –
- Chills
- Constipation
- Coughing
- Decreased Appetite
- Diarrhea
- Fatigue
- Fever and Flu Like Symptoms
- Headache
- Itching
- Muscle Aches
- Nausea and Vomiting
Different types of immunotherapy cause different side effects and some of these side effects can be quite severe as well. CAR T-Cell Therapy which is a type of immunotherapy (provide a link to the article posted on the website regarding the same), can cause a severe side effect known as Cytokine-Release Syndrome (CRS).
Cytokines (chemical messengers that help the T cells carry out their functions) are produced when the CAR T-Cells multiply in the body and attack the cancer cells. The symptoms of CRS can be extremely serious such as low blood pressure, tachycardia and cardiac complications. Along with this it can also cause some serious complications including anaphylaxis, kidney dysfunction and neurological complications.
A patient’s health care team can help to prevent or provide some relief from such symptoms. It becomes imperative that a patient consults their oncologists about these side effects so that they can make a well informed decision about the best possible line of treatment that will cater to them.
Immunotherapy Drugs
Checkpoint Inhibitors, a type of immunotherapy employs medications that have been approved as the standard line of treatment for a wide range of cancers. Some of these drugs include –
- Pembrolizumab
- Atezolizumab
- Durvalumab
Immunotherapy Vs Chemotherapy
One of the 3 modalities of cancer, chemotherapy is one of the standard lines of treatment for a wide range of cancers. While immunotherapy strengthens the immune system and its responses, chemotherapy kills malignant as well as non cancerous cells of the body. Chemotherapy is deemed to be the standard line of treatment for various cancer types and is also used to shrink the size of a the size of a tumor before a patient receives additional lines of treatment such as radiation or surgery. It is also used to eliminate any remaining cancer cells following these treatments (Adjuvant Chemotherapy). Chemotherapy drugs are either regional, which means that they target an area of the body or either systemic which means they enter the bloodstream and attack a cancer that has metastasized. The main goal of this treatment is to obstruct the cell reproduction process that takes place at the various stages of the cell cycle.
The cell cycle is a process that all cells go through to create new ones. Chemotherapy has a greater impact on cancer cells because they undergo this process more quickly than healthy cells. Chemotherapy can harm healthy cells during their regular cell cycle because it permeates the entire body. This is also the reason why chemotherapy induces severe side effects such as hair loss, nausea, bleeding and bruising.
Key Differences Between Immunotherapy and Chemotherapy
Duration of the Treatment
Depending on the exact type of cancer being treated, its stage and the patient’s overall health, the length of chemotherapy and immunotherapy may vary. Chemotherapy treatment usually consists of a number of cycles each lasting to a few weeks to a few months. Depending on the stage and the histology of the cancer, the duration of the treatment may last for a few months, years or even longer.
The duration of immunotherapy treatment depends on several factors as well such as the type of immunotherapy being administered, the stage and histology of the cancer. While certain immunotherapies such as Checkpoint Inhibitors may be administered for a set period of time, there are also immunotherapies that are administered throughout a patient’s lifetime.
Route Of Administration
Depending on the specific therapy, immunotherapy can be given intravenously, by injection or orally. Chemotherapy drugs are usually administered intravenously which means that they are injected directly into the vein through a needle or catheter.
Efficacy For Different Types Of Cancers
While immunotherapy has shown considerable promise in a wide range of cancers, checkpoint inhibitors and CAR T-Cell therapy have demonstrated great potential in the treatment of lung cancer and lymphomas and some types of leukemia such as relapsed or refractory B-cell acute lymphoblastic leukemia (ALL) respectively. Immunotherapy may be used in combination with chemotherapy to treat a wide variety of cancers.
On the other hand, chemotherapy is the standard line of treatment for nearly all types of cancers. It can be administered for patients whose cancer has attained metastasis as well as for patients who have been diagnosed with initial stages of cancer.
Side Effects
Immunotherapy and chemotherapy can both have adverse effects, but they may not all be the same in kind or intensity. Immunotherapy can have mild side effects, such as flu-like symptoms or an injection site reaction. Chemotherapy, on the other hand, is a systemic treatment that carries a higher risk of infection and can result in a variety of side effects, such as fatigue, hair loss, nausea, and vomiting. But after treatment is over, some of the negative effects of chemotherapy might go away. For cancer patients, immunotherapy may generally be less toxic than chemotherapy.
Immunotherapy Cost In India
Immunotherapy cost in India depends entirely on the type of immunotherapy used, the drugs used, the overall treatment plan, the histology of the cancer, the stage of the cancer and the overall health of a patient. Immunotherapy is relatively more affordable than other cancer treatment types and roughly costs between Rs. 2,00,000 – 6,00,000 in the country.
Denvax, one of the premier institutes of immunotherapy in the country specializes in Dendritic Cell Therapy and uses cultivated Dendritic Cells to boost the immune responses of the body. A typical treatment plan at Denvax extends for 6 doses of dendritic cell therapy which can be extended according to the patient’s needs. 6 doses of this therapy costs roughly around Rs. 4,50,000.
Efficacy For Different Types Of Cancers
Breast Cancer – One of the cancers that women worldwide are diagnosed with the most frequently is breast cancer. According to the Cancer Research Society, during their life course , 1 in 8 women and 1 in 1,000 men will experience invasive breast cancer.
Immunotherapy for Breast Cancers
Atezolizumab and Paclitaxel are two immunotherapy drugs that are used for the treatment of metastatic and locally advanced triple negative breast cancer. Breast cancers that test positive for the PD-L1 protein may be treated with atezolizumab. Pembrolizumab is another immunotherapy drug that is commonly used for the treatment of breast cancer.
- Colorectal Cancer – Checkpoint Inhibitors can be used for treating colorectal cancers. The drug pembrolizumab targets PD-1, a protein on T cells in the immune system that normally aids in preventing these cells from attacking other cells in the body. These medications strengthen the immune system’s defense against cancer cells by blocking PD-1 protein. For patients with metastatic or advanced colorectal cancer, pembrolizumab may be used as the initial treatment. Every three or six weeks, it is administered as an intravenous (IV) infusion. For patients with metastatic colorectal cancer that has progressed following chemotherapy treatment, ipilimumab may be offered. Every two to four weeks, it is usually administered as an IV infusion on its own. It is administered every three weeks if ipilimumab is also being used.
- Lung Cancer – Immune checkpoint inhibitors are used as a line of treatment for lung cancer. Targeting PD-1, a protein on specific immune cells (referred to as T cells) that typically aids in preventing these cells from attacking other cells in the body, the commonly used drugs for lung cancer are pembrolizumab, and cemiplimab. These medications strengthen the immune system’s defense against cancer cells by blocking the PD-1 protein. Some tumors may get smaller or grow more slowly as a result of these drugs. Durvalumab and atezolizumab target PD-L1, a PD-1-related protein present on some immune and tumor cells. By blocking this protein, the immune system’s ability to combat cancer cells can be strengthened. This may cause some tumors to shrink or grow more slowly.
Final Note
Immunotherapy has emerged as the fourth modality in cancer treatment over the past decade. Since it boosts the immune system and its responses, it allows our body to identify and ultimately attack cancer cells which otherwise would have evaded these responses. This line of treatment has shown promise in a wide range of cancers and can be used in conjunction with traditional lines of treatment.
Also Read: Types Of Immunotherapy
