How your body can fight cancer with a special type of treatment
Imagine you have cancer, a disease that occurs when abnormal cells grow out of control and invade other parts of your body. How can you treat this disease and stop it from spreading? One of the options you may have is immunotherapy, a special type of treatment that uses your body’s own immune system to fight cancer.
Your immune system is your body’s defense system against harmful substances and organisms, such as bacteria, viruses, fungi, parasites, and even cancer cells. Your immune system consists of various cells and molecules that work together to protect you from infections and diseases. However, sometimes your immune system fails to recognize or destroy cancer cells, or it is weakened by the cancer itself or by other treatments.
Immunotherapy is a type of treatment that helps your immune system to better act against cancer. It can either boost your immune system’s natural ability to fight cancer, or it can give your immune system new tools to find and attack cancer cells.
There are several types of immunotherapy that are used to treat different kinds of cancer. These include:
• Immune checkpoint inhibitors, which are drugs that block certain proteins on the surface of immune cells or cancer cells. These proteins normally act as brakes or checkpoints that prevent the immune system from attacking normal cells. By blocking them, these drugs allow the immune system to unleash a stronger response against cancer cells. For example, some drugs block a protein called PD-1 on immune cells called T cells, or a protein called PD-L1 on cancer cells. These drugs are used to treat cancers such as melanoma, lung cancer, kidney cancer, bladder cancer, and head and neck cancer.
• T-cell transfer therapy, which is a treatment that boosts the natural ability of your T cells to fight cancer. In this treatment, T cells are taken from your tumor or blood. Those that are most active against your cancer are selected or changed in the lab to better attack your cancer cells. They are then grown in large numbers and put back into your body through a vein. This treatment may also be called adoptive cell therapy or CAR T-cell therapy. It is used to treat cancers such as leukemia and lymphoma.
• Monoclonal antibodies, which are immune system proteins made in the lab that are designed to bind to specific targets on cancer cells. Some monoclonal antibodies mark cancer cells so that they will be better seen and destroyed by the immune system. Others block signals that help cancer cells grow and survive. Others carry drugs or radioactive substances that kill cancer cells directly. Monoclonal antibodies are used to treat cancers such as breast cancer, colorectal cancer, lymphoma, and leukemia.
• Cancer vaccines, which are substances that stimulate the immune system to recognize and attack specific antigens on cancer cells. Antigens are any substances that trigger an immune response. Some vaccines are made from killed or weakened cancer cells or parts of them. Others are made from proteins or peptides that mimic antigens on cancer cells. Cancer vaccines can be used to prevent cancers caused by certain viruses, such as cervical cancer caused by human papillomavirus (HPV), or to treat cancers that have already developed, such as prostate cancer.
• Cytokines, which are chemicals that help the immune system communicate and coordinate its actions. Some cytokines boost the activity and growth of immune cells, while others slow them down or change their function. Cytokines can be given as drugs or produced by genetically modified immune cells or tumors. Cytokines are used to treat cancers such as kidney cancer, melanoma, and lymphoma.
Immunotherapy can be given alone or in combination with other treatments, such as surgery, chemotherapy, radiation therapy, or targeted therapy. It can be given through different ways, such as injections under the skin or into a muscle, infusions into a vein, pills or capsules taken by mouth, creams applied on the skin, or implants placed under the skin.
Immunotherapy can have different effects on different people and different cancers. Some people may have a complete response, meaning that their cancer disappears completely. Others may have a partial response, meaning that their cancer shrinks but does not go away completely. Others may have stable disease, meaning that their cancer does not grow or shrink but stays the same. Others may have progressive disease, meaning that their cancer grows or spreads despite the treatment.
Immunotherapy can also cause side effects that vary depending on the type of immunotherapy and the person receiving it. Some common side effects include fatigue, fever, chills, nausea, vomiting, diarrhea, skin rash, itching, pain, swelling, inflammation, infection, and allergic reactions.
Some rare but serious side effects include autoimmune reactions, where the immune system attacks normal organs and tissues, such as the lungs, liver, kidneys, thyroid, heart, brain, or nerves.
These side effects can be mild or severe, and may occur soon after starting the treatment or months later.
They may require additional drugs to suppress the immune system or stop the immunotherapy.
Immunotherapy is an exciting and promising field of research and treatment for many types of cancer. It offers new hope for people who have cancers that do not respond well to other treatments or who have cancers that come back after other treatments. It also offers new insights into how the immune system works and how it can be harnessed to fight diseases. However. immunotherapy is not a cure for all cancersand it does not work for everyone. More research is needed to understand how immunotherapy works and how it can be improved and combined with other treatments to achieve better outcomes for more people with cancer.