Immunotherapy represents the next frontier of cancer treatment and is a therapy that underscores that no cancer is routine. This treatment harnesses the individual’s immune system, expands it and the unleashes it against the cancer. Immunotherapy is providing hope for patients who are out of options, but also in many cases it is a first-line therapy that is not only effective but less harsh than chemotherapy.
How Does Immunotherapy Work?
Immunotherapy (also called immune therapy) is the use of a patient’s immune system to treat cancer.
The immune system protects us from disease-causing viruses, bacteria, fungi and parasites. More than a century of medical evidence strongly suggests that the immune system also plays a role in eliminating precancerous and cancerous cells from the body. Doctors and researchers have long sought ways to boost this natural defense system’s ability to eliminate or prevent cancer.
Cancer cells are cells that are part of the body, but key genes in those cells developed mutations and other changes that cause the cells to grow rapidly, to survive rather than die and to form tumors. Those changes also enable cancer cells to avoid detection by the immune system and enable tumors to grow and spread.
Scientists initially tried to counter this by strengthening patients’ immune response to cancer, but they now know that this is only part of the picture. Research in the past 5 to 10 years has shown that there are also biological mechanisms that suppress the immune system in cancer patients, enabling cancer cells to evade detection by immune cells. So, it is also important to reverse the processes that restrain the immune system from attacking cancer.
This knowledge has led to the development of drugs that block the signals that cause this suppression, freeing immune cells to fight tumors. This therapy is showing tremendous promise, as patients with cancers that have resisted other treatments are responding to these new drugs. An example is the drug nivolumab mentioned below.
Immune System Mechanisms
The immune system uses three main mechanisms to protect the body:
- B cells, which release antibodies that recognize, bind to and eliminate infectious agents and tumor cells;
- T cells, which directly recognize infected cells and cancer cells and kill them;
- Other immune cells, including natural killer (NK) cells and macrophages, that detect infectious agents and cancer cells and then engulf or consume them (a process called phagocytosis).
Types of Immunotherapy
Some of the types of immunotherapy for treating cancer are:
- Cytokine therapy, which uses hormone-like protein molecules that naturally exist within the body to bolster immune responses;
- Monoclonal antibodies, or drugs designed to attach to specified targets in the body and create an immune response that destroys cancer cells. Other monoclonal antibodies are designed to mark cancer cells for easier recognition and destruction by the immune system;
- Adoptive cell transfer, which bolsters the ability of T cells to combat cancer. Scientists remove T cells from a patient’s tumor and isolate the cells that are most active against cancer. Or they may alter the genetic makeup so they can better detect and destroy cancer cells. They then grow these cells in the lab and inject them into the patient, where they attack the tumor;
- Vaccines, which are designed to stimulate the body’s immune system to produce antibodies against specific antigens on a cancer cell. These treatment vaccines are different from vaccines that help prevent disease. However, some are being designed to produce memory B cells that may provide a lasting anticancer response to help keep cancer from recurring;
- Other drugs have been developed to block mechanisms that suppress anticancer immunity. An example is nivolumab, which blocks the PD1 (programmed death) receptor on T cells. Blocking the PD1 receptor frees the T cells to attack cancer cells.
Immunotherapy can be given intravenously (injected into a vein), orally (pill or capsule) or topically (a cream rubbed onto the skin). Like other cancer treatments, immunotherapy can cause side effects, including skin reactions, fever, chills, fatigue, nausea, headache, sinus congestion, diarrhea and risk of infection. In rare cases, it causes severe allergic reactions.
The frequency of treatment depends on a number of factors, such as the type and stage of cancer, the type of immunotherapy being administered and the body’s reaction to the therapy. Patients receiving immunotherapy will be frequently monitored by their oncologist through tests, exams and scans that will determine whether the therapy is working and record any effects it may be having on the body.
Although immunotherapy is not as widely used for treating cancer as surgery, radiation and chemotherapy, it is proving to be effective in more and more patients as researchers understand more about the immune system and devise ways to manipulate it for individualized treatment. Clinical trials are under way at Ohio State to test possible new immunotherapies for patients with cancer in its many forms.
The OSUCCC – James is achieving impressive results through clinical trials with some patients diagnosed with these cancers:
- Head and Neck
- Multiple Myeloma
If you’ve been diagnosed with cancer, would like a second opinion or would like to speak with a cancer specialist, please call The James Line at 800-293-5066 or 614-293-5066 to make an appointment.
The James Cancer-Free World Podcast
Dr. Carbone is the director of The James Thoracic Center and is a lung cancer specialist. He’s also an expert on a new and very exciting cancer treatment: immunotherapy. Immunotherapy helps the body’s immune system recognize, attack and kill cancer cells and is a big step forward in creating a cancer-free world.