How do you know if your myeloma treatment is working? Dr. Joshua Richter, a myeloma specialist, reviews how treatment response is measured in myeloma and why it’s important to share any symptoms or side effects with the healthcare team.
Dr. Joshua Richter is director of Multiple Myeloma at the Blavatnik Family – Chelsea Medical Center at Mount Sinai. He also serves as Assistant Professor of Medicine in The Tisch Cancer Institute, Division of Hematology and Medical Oncology. Learn more about Dr. Richter, here.
So, once treatment has begun, how do you know if it’s working?
Absolutely. So, the majority of myeloma patients are what we call “secretory.” And by “secretory,” it means that the cancer cells secrete a protein that we can measure in the blood either an M-spike, which is an intact immunoglobulin like IgG and kappa, or a free light chain. It doesn’t make that IgG part, just a free kappa or free lambda. And basically, when these protein levels go up, we know the cancer cells are growing. When these go down, we know we’re killing the cancer cells. And we actually call your remission based on how much we lower it.
If we lower it 25 to 49 percent, that’s an MR or minor response, or minor remission. 50 to 89 percent is a PR, partial response, partial remission. 90 to 99 percent is a VGPR, a very good partial remission, and then all gone in the blood and then we do a bone marrow is a CR or complete remission.
For some people, their disease can be non-secretory where the cancer cells don’t make that protein anymore.
And for those people, we need to do regular imaging to see if they have growths of myeloma we call plasmacytomas, or unfortunately, we need to do regular bone marrow biopsies to see how much of the bad cells are growing inside the marrow.
All right. How do you know when it’s time to switch treatment?
So, in general, when patients fulfill the criteria for what we call “progressive disease” or PD, that’s the time to change, or intolerance that regardless of how we dose adjust, dose hold or add supportive care, it’s not tolerable for a patient to continue.
Intolerance is a very personal thing. There are things that certain people are willing to tolerate and others not. So, we try to adjust that. Just like we have criteria for response, PR, VGPR, we have criteria for progression. And in general, it’s a 25 percent increase from your baseline and 0.5 increase in your M-spike or 100 increase in your light chains. So, when the disease numbers are going up, we tend to switch.
Now, people may say, “But I feel fine,” and a lot of this is because you’re diagnosed with an amount of disease up here. We get you in remission, you’re down here. And once you go like this, we can see the writing on the wall and we’d rather be proactive than reactive. So, instead of waiting until the numbers get up here to cause trouble, once it goes from there to there, we intervene, change therapy to bring it back down.
Dr. Richter, why is it essential for patients to share any issues they may be having with their healthcare team?
It is absolutely crucial because some things that may be very, very minor to them may be the tip of the iceberg of something very, very worrisome that we really need to investigate because sometimes, little problems are little now, and over time, they can become problems that we can’t so easily reverse. So, things like neuropathy, fatigue, or actually better yet, what I tell my patients is, “You know your body. If there is something out of the ordinary, big or small, let us know.”
And I would way rather a patient tell me 10 things in a row that mean nothing than not tell me about that one thing that means something.
So, for example, one of the disorders that’s associated with myeloma is called amyloidosis.
And when amyloid attacks the kidneys, you start to have protein in the urine, and this looks like bubbles, like foam in the urine. So, if someone has no foam when they urinate, and then over a period of months to years, they’re starting to notice lots of foam, tell me because that means we may need to look for things like amyloid.
So, really any time something changes.