Traditionally, cancer has been treated with methods that attack the cancer directly, such as chemotherapy, radiation or surgery. Immunotherapy is a newer treatment that works differently. Instead of attacking the cancer cells directly, immunotherapy helps your body’s immune system attack the cancer.
There are different types of immunotherapies being used to treat cancer. The most common is a group of drugs called checkpoint inhibitors. Checkpoints are like the brake pedals in the immune system. They are our body’s way of telling the immune system to stop attacking, thereby preventing the immune system from attacking healthy cells. Cancer cells can use these brake pedals to evade the immune system. Inhibitors block these checkpoints put in place by the cancer cells, thereby allowing your immune system to destroy the cancer cells.
This treatment has led to long-term remission in some cancer types, raising the hope of a cure for patients. For instance, in a trial of advanced melanoma patients who received this type of treatment, nearly 50 percent were alive more than six years after treatment. Twenty years ago, the average life expectancy for these patients would have been six to seven months.
A different type of immunotherapy, known as CAR T-cell therapy, takes a sample of a patient’s immune cells, T-cells, then re-engineers them in a lab. When these cells are reinfused into the patient, they recognize the cancer cells and destroy them.
In 2012, CAR T-cell treatment was first administered to a child, who had been diagnosed with a type of leukemia at age 5. She had exhausted all treatment options before enrolling into an experimental clinical trial using CAR T-cell therapy. She is now 17 and cancer free for a decade.
Immunotherapy is one the most important advances we have made in cancer treatment in recent decades, but there are still advances to be made, as immunotherapy works better on some cancer types than others. It can be a miracle for some but fail to work for others. Current research in the field is exploring how we can improve immunotherapy to extend the incredible successes we are seeing in some patients to all cancer patients.
It’s exciting to anticipate the developments we will see over the next decade; it is a hopeful time for cancer therapy.
Dr. Pamela Tuli is a hematologist-oncologist practicing with The Medical Oncology Group – Memorial Physician Clinics. She can be contacted at (228)-575-1234.