The effectiveness of immunotherapy as a cancer treatment has drawn more attention from the public recently. Since its durability is longer lasting than chemotherapy and it is effective for about 80% of lung cancer patients, immunotherapy is now viewed as the new preferred treatment for lung cancer. Together with the PDL-1 protein test to predict the response of individual patients to immunotherapy, the appropriate treatment can then be administered sooner. Patients no longer need to waste money and time receiving unsuitable treatment.
The Relationship Between Immunity and Cancer
To effectively understand immunotherapy, we must learn about the mechanism of our body’s immune system first. Under normal circumstances, when the immune system identifies some bacteria, viruses, or abnormal cells (such as cancer cells) in the body, an immune response will be triggered. Some immune cells are emitted in our system to eliminate the unwanted cells. At the same time, some receptors in the immune system bind to some inhibitory ligands to inhibit the immune response and thus avoid overreaction.
Cancer cells can affect this mechanism and hinder an immune response. For example, some lung cancer cells express more PD-L1 ligand. PD-L1 ligand will bind to inhibitory receptors to suppress the immune response so that the body cannot eliminate the cancer cells through the immune system.
Immune Checkpoint Inhibitor
However, scientists have found that specific drugs can suppress the effect of cancer cells on the immune system effectively and improve the ability of the immune system to fight against cancer cells.
The U.S. Food and Drug Administration has approved several immunotherapy drugs for the treatment of lung cancer, melanoma, head and neck cancer, renal cell cancer, and other cancers. In Hong Kong, immunotherapy drugs have been registered and can be used in the treatment of melanoma and lung cancer.
Immunotherapy drugs are antibodies which are proteins. They have fewer and milder side effects, lower risk of drug resistance and longer effects than chemical drugs in chemotherapy and targeted drugs. It can be injected intravenously into the patient’s body every two to three weeks, taking about an hour each time. In terms of effectiveness, studies have found that, as a second-line treatment of lung cancer, the one-year survival rate of patients with immunotherapy was higher than those who received chemotherapy.
Protein Test to Ensure the Effectiveness of Immunotherapy
According to current data, immunotherapy is effective for 80% of lung cancer patients. If the cancer cells express PD-L1 ligand, it is effective for about 40% to 50% of patients. Therefore, with the PD-L1 protein test to check the presence of PD-L1 ligand in a patient’s cancer cells, the chance of ineffective treatment can be reduced. As a result, patients can then avoid wasting their money and time on ineffective treatment.
Source: Dr Au Siu Kie, Specialist in Clinical Oncology at Hong Kong Adventist Hospital – Stubbs Road
