Current Ways to Diagnose and Monitor Myeloma
Current diagnosis and monitoring of myeloma is traditionally done using a combination of tests and procedures: Learn more about the main tests used to diagnose and monitor myeloma in the section What Tests Do You Need?
For more details on standard-of-care testing, please see International Myeloma Working Group (IMWG) Criteria for the Diagnosis of Multiple Myeloma. Despite the availability of multiple diagnostic tests, scientists and researchers continually work to develop new and improved diagnostics and prognostic tests for myeloma. Below are some of the newest and most promising emerging tools.
Minimal Residual Disease (MRD) Testing
Minimal residual disease (MRD) refers to the small number of myeloma cells that may survive in your body after treatment. The amount of these cells is so small that you may not show any signs or symptoms of myeloma. Also, most of the time, the number of cells is too small to be detected through standard testing. MRD tests are so sensitive that they can detect 1 myeloma cell in 1 million healthy cells.
MRD testing is used to help know if your myeloma is in remission, if you are likely to relapse, and if you need further treatment.
Currently, the standard approach to MRD testing is to assess the number of myeloma cells present in a bone marrow sample. Broadly, the following two techniques have been used:
- Genetic sequence analysis: Next Generation Sequencing (NGS)
- Flow cytometry: Next Generation Flow (NGF)
Even though NGS is an FDA-approved test, it’s exact role in disease-monitoring is not yet established. The NGF method is not yet FDA-approved, so no protocols exist for standard disease-monitoring using NGF.
The i2TEAMM, a group brought together by the IMF, is engaged with the FDA in seeking approval for MRD as an early endpoint to assess response in clinical trials. As of April 12, 2024, the the Oncologic Drug Advisory Committee (ODAC) unanimously voted in favor (12-0) of using minimal residual disease (MRD) as an early endpoint for accelerated approval in multiple myeloma clinical trials. Read the full press release here.
In clinical practice, no accepted standard of care is established. If MRD is undetected, this status is obviously excellent. Yet, more trial information is required to guide decision-making. Sustained MRD that is undetected for six months or one year is particularly promising in terms of potential long-term remissions or improved survival.
However, is it safe or recommended to stop treatment with sustained MRD? Conversely, if residual disease is detected, is new treatment required? These questions remain open.
MRD test results must be discussed with your doctor to assess any options for changes to treatment or not. An MRD-negative status is obviously good, but an MRD-positive status may indicate a low (and potentially stable) level or residual disease. This status does not necessarily indicate need for treatment changes.
For more information on MRD, please visit the International Myeloma Working Group consensus criteria for response and minimal residual disease assessment in multiple myeloma.
Mass Spectrometry Testing
Mass spectrometry (“mass spec”) is a simple blood test. It is a highly sensitive new method to detect and measure the precise amount of M-protein in the blood. Mass spec is helpful in the diagnosis and monitoring of MGUS, smoldering multiple myeloma (SMM), and active myeloma. During assessment of response to treatment, much deeper levels of response and much earlier indicators of response can be detected with mass spec.
While mass spec is a simple blood test, it is currently conducted at only a few reference laboratories, such as Mayo Clinic Medical Labs in Rochester, Minnesota. It is anticipated that mass spec will be approved by the FDA in the near future. If approved, mass spec testing may be made more available.
In February 2021, Blood Cancer Journal published a report by the International Myeloma Working Group (IMWG) Mass Spectrometry Committee on the benefits of mass spec methods in diagnosing and monitoring patients with myeloma and related disorders. Mass spec can distinguish between very low levels of M-protein and blood levels of monoclonal antibodies used to treat myeloma. Making this distinction can confirm if the patient has achieved complete response (CR).
In December 2022, at the 64th Annual Meeting & Exposition of the American Society of Hematology (ASH), the oral presentation of abstract 866 compared the impact of mass spec in peripheral blood vs. next-generation flow (NGF) in bone marrow to assess MRD in newly diagnosed myeloma patients receiving maintenance as part of the GEM2014MAIN clinical trial. The complementary testing in this study demonstrated similar ability to predict a shorter or a longer remission.
Since mass spec is a test performed in the blood, it can be used as a screening method: if mass spec is negative, then this could indicate a need for bone marrow testing to check if residual disease can be found.