How is Multiple Myeloma Diagnosed?
Basics of Myeloma
What is myeloma?
Dr. Rafael Fonseca:
Multiple myeloma belongs to the group of diseases we think about when we think about blood cancers. Specifically, myeloma is a form of adult bone marrow cancer that comes about when plasma cells convert into malignant cells.
Under normal circumstances, plasma cells help protect our bodies. They produce the antibodies that give us immunity. Occasionally, those cells become malignant, and that’s what we call myeloma.
These malignant cells are usually restricted to the space inside the bones called the bone marrow. There are a number of problems that can come about because of the growth of malignant cells from myeloma. The cells grow, and they take up space.
A person may present with fatigue because they have anemia. The cells can also cause problems in the bones. They can erode the bone structures.
This can cause pain or in more extreme cases, even fractures. It also releases some of the calcium that our bones have into the bloodstream. Patients may have a high calcium content in their blood.
Myeloma cells also produce a type of protein. Fragments of the protein can flow down into the urine. That can cause problems in the kidney in the form of renal failure.
»MORE: What is multiple myeloma?
Dr. Nina Shah:
Multiple myeloma is a cancer of a cell called plasma cell. A plasma cell is part of your immune system. Normally your immune system is made to fight viruses and bacteria and one of its soldiers is called a plasma cell.
Particularly, plasma cells are supposed to produce antibodies, which we’ve heard a lot about recently. COVID antibodies, antibodies to zoster, all these things.
These antibodies are proteins that help you fight and tag bad things so your immune system can know to kill those things.
In the case of multiple myeloma, one of these plasma cells goes haywire. It grows out of proportion to the other cells, and that’s really the definition of cancer.
When one cell gets selfish and replicates its own clone, it takes up the resources of the other cells. That’s what happens in multiple myeloma.
One plasma cell grows and it starts taking up the space in the bone marrow. It starts producing a protein that eats the bone around it and that’s why people can have holes in their bones, or lytic lesions.
Then the protein that it produces—that antibody is now one antibody. It’s not a variety of antibodies. It’s just that one clone.
That’s why you will often hear the term monoclonal protein or monoclonal or clonal protein, M protein. That’s something that we can use to measure how many plasma cells there are.
It’s like the petals on the flower; the more petals you see around, the more you know they have flowers and that’s what we often use to measure in the blood.
The proteins that are produced from these cells can be in such high quantities that they also can have detrimental effects. That’s why some people with myeloma will say, “Well, my light chains were really up.”
That’s part of that M protein, those antibodies, and they can clog up the kidneys.
You hear about multiple myeloma as a disease that affects almost every part of the body—the bones, the kidneys, the blood system, and it all comes from having this one immune cell get a little out of whack. It’s supposed to help you, but in this case, it’s harming you.
How is a person diagnosed with multiple myeloma?
Dr. Rafael Fonseca:
For most patients that we diagnose, they’ll come because they’re having some symptoms. Some might come because they have a history of back pain. Sometimes they’re seen in the hospital because of kidney problems and it’s found out that those problems are due to the multiple myeloma.
Maybe a general practitioner finds that the person has anemia and it’s not otherwise explained. Then, the patient would go to a hematologist and would ultimately get diagnosed.
There is a fraction of patients who are diagnosed with a premalignant condition called smoldering multiple myeloma where they may have abnormal cells and have detectable levels of the protein in their blood and urine but not show symptoms. The majority of those patients will not require treatment.
What are the different types of multiple myeloma?
There is an early step called monoclonal gammopathy of undetermined significance. That’s a mouthful, so it’s usually referred to as MGUS.
That condition is when there’s very discrete growth of the plasma cells, usually that they’re going to be less than 10-percent of the cells in a person’s bone marrow.
Patients with this will not have any of the features I mentioned like anemia or kidney problems. This is actually quite common. More than two-percent of people over the age of 50 have this.
This can evolve a little more. If the number of cells is more than 10% of the marrow, this is called smoldering multiple myeloma. It will remain as such for as long as there is no evidence of complication.
Once we see that someone has complications, that’s when we say they have multiple myeloma, active myeloma or simply, “myeloma.” That’s when people require treatment.
We spend a lot of our time trying to define the boundaries between those three groups. In fact, where the boundaries are has changed recently.
So much so that we think there are some patients who have more advanced cases of smoldering multiple myeloma who should go ahead and start treatment.
What are the chances of it relapsing or being refractory
Dr. Nina Shah:
Unfortunately, multiple myeloma is considered an incurable disease, but it is a disease that one person can live with for a very long time.
We have patients who’ve lived 10, 15 years with it. It really depends on where that myeloma is going and what it’s like.
Sometimes we can predict that and sometimes we can’t, but on average, our standard myeloma patients are living longer than 10 years, at least, because we have new therapies.
What I tell all myeloma patients I meet is that, “You’ve been newly diagnosed and we’re starting therapy on you. We’re hoping that we can stretch out this time as long as possible so that we can have this first remission, meaning the first time you have a response that lasts as long as possible so that you don’t have to worry about it and you get back to your life and start being a person and not a patient.”
Is there a standard of care?
Dr. Rafael Fonseca:
There are several guidelines that are published. One of the most common is called NCCN. From a patient perspective, that can be daunting and complex. I recommend starting with a patient organization like one of the ones I mentioned.
We at Mayo have a set of guidelines we provide. It’s mostly directed towards providers, but it’s simple enough that they can be understood even if you’re not in medicine. They’re available online at msmart.org. That provides a general description of what we would prescribe for patients in different situations.