The Mainichi Shimbun answers questions readers may have about immunotherapy techniques being used to fight cancer.
Question: There has been talk lately about a cancer treatment using the body's immune system. What does it involve?
Answer: The human immune system protects the body from external threats like bacteria and viruses, but it can also fight cancer cells that develop inside the body. Being diagnosed with cancer in short means that the number of cancer cells has increased at such a rapid rate that the immune system cannot keep up with removing them. Opdivo and other cancer immunotherapy medication works by blocking cancer cells' ability to hide from the body's immune system cells, enabling the power of the patient's immune system to eliminate cancer cells .
Q: I saw an advertisement on boosting the immune system to fight cancer. Is that the same thing?
A: Immunotherapy has been researched as the "fourth type of cancer treatment" after surgical treatment to remove tumors, chemotherapy and radiation therapy. However, there are currently no immunotherapy treatments whose effects have been confirmed and which have been approved for use in Japan. Currently immunotherapy is only available at a high price that must be paid for completely out of the pockets of the patients themselves. It is important to differentiate these treatments from approved medications such as Opdivo.
Q: Is it true a new immunotherapy called CAR-T (chimeric antigen receptor T-cell) therapy is being utilized in the United States?
A: CAR-T treatment is for acute lymphoblastic leukemia, a type of cancer which is common in children and young adults. Immune system cells called T-cells are extracted from a patient's blood, and engineered in a lab to produce CAR cells on their surface, which allow the immune cells to target cancer cells. The cells are then returned to the patient's blood . In clinical trials, 80 percent of patients who underwent the treatment showed significant improvements in their condition. However, when the CAR-T cells multiplied in the body, patients were found to have serious symptoms such as low blood pressure and respiratory failure. Immunotherapy is often thought to be very safe, but it is important to recognize that it also carries side effects. (Answers by Satoshi Takano, Medical Welfare News Department)