Science and technology have advanced a lot over time and it have brought about a revolution in the medical industry. However, the introduction of different immunotherapies has opened a new dimension for the treatment of different types of cancer. Immunotherapy is a type of cancer treatment that uses substances made by the body or in the lab to boost the immune system’s responses. Relatively new in comparison to other traditional forms of treatment such as chemotherapy, radiation therapy and surgery, immunotherapy has emerged as a viable option for various kinds of cancers over the past 10 years. Immunotherapy can be used as a stand-alone form of treatment or can be employed as an adjuvant form of treatment, i.e. in combination with the other 3 modalities of cancer.
Understanding The Role of Immunotherapy in Treating Cancer
The immune system is a collection of organs and tissues that work together to protect a person from any foreign pathogen or disease. The immune cells of the body travel through your body to protect it from any germs that may cause infections. The immune system keeps track of all the substances that are found in your body. Any new substance that the immune system does not recognize raises an alarm and triggers an immune response, thereby allowing the immune system to attack it. The immune system uses the proteins that are found on the surface of the cells to identify whether a substance is harmful or not. When it comes to cancer cells, the immune system faces difficulty in recognizing and attacking them. This is primarily due to the fact that cancer cells are the body’s own healthy cells that have gone rogue and have undergone mutational changes. Since cancer develops in the healthy cells of the body, the immune system does not recognize them as a foreign entity. Since the immune system may not be equipped to deal with the immune system all by itself, immunotherapy as a line of treatment attempts to boost the immune system and its responses.
Different Types of Immunotherapy
- Non-specific immune stimulation: This is a type of immunotherapy that stimulates a patient’s immune system in a general way. In non-specific immune stimulation, drugs or other substances are used to increase the overall immune response, which can help kill cancer cells. For example, if any patient has had surgery to remove bladder cancer, that patient might also be treated with a substance called BCG. When BCG is put into the bladder, it can stimulate a non-specific immune response that kills cancer cells that remain in the bladder even after the surgical procedure is over. This reduces the chances of cancer recurrence.
- T-cell transfer therapy: T-cell transfer therapy is another type of immune therapy that uses T-cells. T-cells are a type of immune cell. These are powerful weapons that our immune system uses to fight cancer. For T-cell transfer therapy, T-cells are taken from a patient’s body and altered in the laboratory. Multiple copies of these specially treated T-cells are then grown in the laboratory and inserted back into the patient’s body to fight cancer.
- Immune checkpoint inhibitors: immune checkpoint inhibitors are a third type of immunotherapy. The immune checkpoints on cell surfaces help control an immune response. Usually, immune checkpoints keep T-cells inactive, that is, in an “off” state, until they are needed. This prevents the T-cells from harming any normal cell. Cancer cells can take advantage of these checkpoints to switch T cells off. This prevents the cancer cells from being killed. Immune checkpoint inhibitors refer to substances that block the checkpoints. Thus, the T-cells are free to attack the cancer cells.
Advancement in Immunotherapy
- Bispecific Antibodies: Precision Targeting
Bispecific antibodies are a class of immunotherapeutic agents designed to simultaneously bind to both cancer cells and immune cells, facilitating targeted destruction of the tumour. Blinatumomab, approved for certain types of leukaemia, exemplifies the potential of bispecific antibodies to redirect the immune system to precisely target cancer cells. Ongoing research aims to expand the application of bispecific antibodies to a broader range of cancers, enhancing their therapeutic impact.
- Adoptive Cell Transfer: Enhancing Natural Defenses
Adoptive cell transfer involves isolating and expanding immune cells, such as tumour-infiltrating lymphocytes (TILs), outside the body and then reintroducing them to target and eliminate cancer cells. This approach has shown promise in treating melanoma and other solid tumours. The continuous refinement of adoptive cell transfer techniques, coupled with advances in genetic engineering, holds the potential to broaden its applicability across various cancer types.
- Monoclonal Antibodies
Monoclonal antibodies are molecules specially designed in the lab that are able to mimic the immune system’s ability to fight against harmful pathogens. In the treatment of cancer, these monoclonal antibodies are used so that they identify and bind to specific proteins on the surface of cancer cells. Rituximab and Trastuzumab are monoclonal antibodies used to treat different types of cancer, such as lymphoma and breast cancer.
Challenges and Future Directions
While strides in cancer immunotherapy are undoubtedly promising, challenges persist. Not all patients respond equally to these treatments, and there can be immune-related side effects. Moreover, the high cost of immunotherapies poses a significant barrier to widespread accessibility. The future of cancer immunotherapy lies in overcoming these challenges and unlocking its full potential. Ongoing research explores combination therapies, personalised treatment approaches, and biomarkers that can predict patient response. The quest for identifying new targets and refining existing techniques remains crucial for expanding the spectrum of cancers amenable to immunotherapy.
The advancements in immunotherapy for treating cancer serve as a ray of hope in the field of cancer diagnosis and treatment. With all the technologies and approaches used in immunotherapy, it aims to provide patients with a more compact, personalized, and targeted solution. It has widened the availability of options available for treating different types of cancer and changed the dynamics and landscape of cancer treatment.
As the process of immunotherapy is still under much research, the future seems very promising. Further studies and advancements can bring out more potential and effective ways to use immunotherapy to combat cancer.
