If Myeloma Cells are Found in the Blood, Do They Predict Myeloma Progression in MGUS and Smoldering Myeloma?

If multiple myeloma cells are found in blood samples (outside of the bone marrow), do they predict MGUS and smoldering patients who will progress to active myeloma? Dr. Brendan Weiss of the Abramson Cancer Center at the University of Pennsylvania is leading a study to find out.

The "watch and wait" approach for MGUS and smoldering myeloma patients can be emotionally daunting. Researchers are looking at many new ways to determine whether patients are high-risk, normal risk or low-risk; distinctions that matter a great deal to patients. A new test that looks at the number of Circulating Multiple Myeloma Cells (CMCCs) may help to predict who progresses and who does not. Building on studies previously done at the Mayo Clinic, Dr. Weiss describes why this simple test may be very useful:

So it’s been known for many years that using different techniques, these cells can be found floating in the blood. And in patients with more advanced myeloma, there is generally more cells in the blood than in patients with less advanced myeloma. And also in some studies that have been done at the Mayo Clinic using their own technology in both MGUS and smoldering, the amount of circulating cells in the blood seems to result in a shorter time to development of myeloma. So detecting the circulating myeloma cells seems to capture another aspect of the biology of the myeloma precursor conditions namely the active spreading of the myeloma cells in the blood to other sites of the skeleton which is something that is not directly captured by our other tests.

Although testing the myeloma cells in the blood is not a new idea, the test is not widely used today.

This is not a new idea per se. Other groups have looked at the ability to detect and count the amount of myeloma cells that are circulating in the blood and they’ve used different techniques. However, those techniques either are very labor intensive or have not been developed for use at other centers. So they’re not widely available.

The test has been used in other solid tumor cancers. The test is a simple blood draw and test results are quickly obtained.

The advantage of this technology is that it is an extension of a technology that was developed years ago that is called CELLSEARCH and it was originally developed for detection of very rare cells in the blood in patients with other kinds of cancers, so in breast cancer, colon cancer, prostate cancer as an example. In those diseases, there are very few circulating cells generally compared to blood cancers so they had to develop a technique to enrich the sample of the possible circulating tumor cell and then classify them.

The other advantage of the technology, in addition to be able to find rare cells, is it is mostly an automated process. There’s only a modest amount of actual human operator required for each individual sample so many samples can be done with less work and the turnaround time is much quicker for the results. So because of that, this could be easily used in the clinical lab.

And one other advantage I should bring up is that when the blood is drawn from the patient, it’s stable for up to four days. And so the other ways of looking at circulating myeloma cells require that the sample be processed the same day.

So it has a lot of possible advantages for both the ability to detect rare cells but also in pragmatic terms it can be used pretty easily in the clinic.

Why is the number of cells important? It may help uncover how myeloma spreads throughout the skeleton.

When I speak to patients about myeloma, I always explain that the reason the disease is called multiple myeloma is that term means that it’s a cancer of many bone marrow tumors. If one were to look at a skeletal survey of a myeloma patient and see all those different lesions, those are different deposits of myeloma cells in the skeleton. And so there must be a way for the myeloma cells to go from one part of the skeleton to another and have these deposits.

Since MGUS and smoldering myeloma patients are already being observed for disease progression, this is an easy study to join. It uses standard blood and bone marrow biopsy tests for evaluation but adds the CMMC test. The study will see whether having circulating myeloma cells signals a high risk of progression to myeloma. A secondary goal is to match these CMMCs with the Mayo Clinic's MGUS/SMM models that use deeper genetics testing. Other factors such as gene expression, the bone marrow microenvironment and general data gathering will be reviewed.

For more information about this study and if you would like to enroll, first review the description on www.clinicaltrials.gov and then contact Dr. Brendan Weiss at  855-216-0098 or email penncancertrials@emergingmed.com.