What is Cancer Genomic Medicine (Cancer Gene Panel Testing)?
Cancer genomic medicine involves analyzing the genes of cancer cells to select treatments best suited for the patient. Genes contain information that directs the production of proteins, which control bodily functions. If genes are damaged, the production of proteins can be altered, leading to abnormal cell behavior, which may result in the formation of cancer cells. In cancer genomic medicine, a test is conducted on cancer cells to determine which genes are damaged. This test is called the “cancer gene panel test” (Fig. 1).
The test can simultaneously examine more than 100 genes associated with various cancers. If damage is found in a gene, using a drug that targets this specific damage may improve treatment outcomes. Such drugs are called molecular targeted therapies. Molecular targeted therapies are designed to work against specific gene damage. Since they target only cancer cells, they tend to have fewer side effects compared to general chemotherapy drugs.
Eligibility for Cancer Gene Panel Testing
Individuals eligible for cancer genomic medicine must meet the following criteria: the cancer must be a solid tumor located in an organ (not blood cancer); there must be no standard treatment available, or standard treatment must have been completed or is expected to be completed; the overall health status must be good; and the primary physician must determine that the patient meets the required standards. If these conditions are met, cancer genomic medicine can be covered by insurance. For insurance coverage, the cost of the cancer gene panel test is 168,000 yen with a 30% out-of-pocket payment. Even if the conditions are not met, cancer genomic medicine can still be accessed through self-pay treatment. In this case, the cost of the cancer gene panel test ranges from 400,000 to 1,000,000 yen. The drugs selected based on the test results would also be self-funded (Fig. 2).
As of September 2024, 268 hospitals across the country, including Tokushima University Hospital, offer cancer genomic medicine.
Points to Consider When Undergoing Cancer Gene Panel Testing
Cancer genomic medicine is not a cure-all. Even after testing, there may be cases where no genetic damage is found, or even if it is found, there may be no drugs available. Additionally, even when drugs are available, they are not always effective. Currently, insurance coverage is available only when standard treatments have ended or are no longer effective. However, it may be possible to participate in clinical trials or research, such as advanced medical care. It is currently estimated that only about 10% of all individuals who undergo a cancer gene panel test use a medicine that is suited to them (including clinical trials). A cancer gene panel test may also reveal a gene that predisposes individuals to cancer. This is called a “secondary finding.” Secondary findings do not mean that you will get the disease now, but they may affect your future health. Some individuals may not want to know about secondary findings. In such cases, you can choose not to receive the results. However, some may prefer to be informed. In this case, hospital experts will be available to discuss the results with you so that you can better understand them. Cancer genomic medicine remains a new field of research. It is expected that more genes and genomes will be examined in the future, leading to more accurate diagnosis and prognosis prediction, and to the development of new treatments, such as additional molecularly targeted therapies and immune checkpoint inhibitors.