What Is a FISH Test in Multiple Myeloma?
Myeloma genetics is an important piece of the myeloma puzzle. If we know what type of myeloma we have, we can see if there are patterns of treatments received and resulting outcomes. The most commonly run genetics test is called the FISH test.
A fluorescence in situ hybridization test (FISH) maps out the genetic material of a cell. It uses special fluorescent dyes that only attach to specific parts of chromosomes. FISH can find most chromosome changes (such as deletions or translocations) that can be seen under a microscope in standard cytogenetic tests, as well as some changes too small to be seen with usual cytogenetic testing. It can detect genetic abnormalities--specifically for cancer. It is used to diagnose certain types of cancer, and can somewhat predict a patient's outcome and susceptibility to chemotherapy treatment.
Changes in the cancer cell genes could make the cell:
- produce particular proteins
- make more of the normal amount of protein
- completely stop making a protein
The FISH test is run from a bone marrow biopsy sample and helps researchers and doctors better know what exactly your cancer is and how to best treat it. The FISH test should be run on only CD138 selected cells. Many myeloma experts like Sagar Lonial, MD of Emory University have remarked how startlingly usual it is that the test is run incorrectly on the entire sample. If the test is run on the whole sample, the results are not as accurate.
The important thing to know about the FISH test is that you get what you test for. In other words, your doctor will have to request that the multiple myeloma panel is run against the sample. If the panel is not run that is looking for common myeloma genetic features such as the 11;14 translocation, gain of 1q or deletion 17p, of course the results will not show the correct findings.
This test should be run at diagnosis and at relapse where there is measurable disease. Your genetic results can be added to your profile in a new tool called HealthTree that will help myeloma patients find patterns of treatments and outcomes based on myeloma genetics. Create a HealthTree profile and if you need help reading the test results, you can upload your printout and we can help enter the information for you.
The FISH test is the most commonly available test at most centers and can be run inexpensively. It should be used for all myeloma patients, so ask your doctor if this test is right for you.