A beta-2 microglobulin tumor marker test measures the amount of a protein called beta-2 microglobulin (B2M) in your body fluids. The test usually uses a sample of your blood. It may also be done using urine (pee) or in rare cases cerebrospinal fluid (CSF).
A beta-2 microglobulin tumor marker test can't diagnose cancer or any other condition. That's because there are so many conditions that can cause high levels of B2M. But if you've already been diagnosed with one of these blood and bone marrow cancers, a B2M test can provide important information about your cancer including:
A beta-2 microglobulin test usually uses a sample of your blood. In certain cases, you may need to provide a 24-hour urine sample, which means collecting all your urine for a full day. If your provider suspects that cancer has spread to your brain or spine, you may have a cerebrospinal fluid (CSF) analysis.
df19127ead