Dr. Jorge Castillo of Dana-Farber Cancer Institute provides an overview of Waldenström macroglobulinemia (WM) and how the condition presents and progresses.
Dr. Jorge Castillo is Clinical Director at the Bing Center for Waldenström Macroglobulinemia Dana-Farber Cancer Institute and Assistant Professor of Medicine at Harvard Medical School. Learn more about Dr. Castillo, here.
Let’s start with the very basic. What is Waldenstrom macroglobulinemia?
Yeah, Waldenstrom’s macro – it’s a mouthful.
I can just call it WM for ease.
It is a blood cancer, and in this blood cancer, the malignant cells are nesting in the bone marrow. And not only that. These malignant cells kind of secrete, produce, a protein called IgM.
IgM is an antibody that should be protecting us from infections, and in a normal state, we all have a little bit of IgM, and that’s a good thing. But in these patients, with these malignant cells, as these cells accumulate in the marrow, they actually increase the levels of IgM in our patients, and that can translate into a number of different symptoms, which we will probably talk about later.
Yes. How is it staged?
So, the staging is a very interesting aspect. So, when we think about cancer, we think about stage I is in one spot, stage II in another spot, stage III, right, and it gets more extensive as we go along. That doesn’t really apply to Waldenstrom’s. Waldenstrom’s is a whole-body disease right from the start. The main reason for that is because it’s a disease of the bone marrow, and we all have bone marrow in all our bones, from our skull all the way to the great toe, so if you were to get a sample from each bone space, we would find the malignant cells there. So, this is a disease that is a whole-body disease right from the start, so therefore, there’s no stage I, II, or III. That is just the way we envision this.
How does the condition progress?
So, it’s interesting because a number of the patients that we see in my clinic are actually asymptomatic at the time of the presentation. I would say maybe about a third of the patients I see in my clinic that were diagnosed with this disease for other reasons. They either had an abnormal laboratory value or an abnormal imaging study or some other reason. And when they come, they are worked up. Initially, they are found to have these malignant cells and these IgM elevation, but they have no other problems whatsoever.
So, I would say most patients will be asymptomatic at the beginning of the disease, and probably they will be asymptomatic for years before the symptoms actually do start. So, what happens is the malignant cells start taking over the bone marrow space, and it reaches a point in which the bone marrow, the healthy bone marrow, doesn’t have space to produce the normal cells that they should produce.
So, the first things that we tend to see in these patients is anemia, so the hemoglobin level starts dropping.
The red cells are the first ones that are being affected by this process so that the anemia is being seen first. If we leave that for a long time, then the other blood cells will decrease also, the white blood cells and the platelets over time. But the first one is almost always the anemia. And obviously, that, patients feel tired. They feel short of breath. They feel fatigued and all of that.
Now, the IgM itself can cause other problems on their own. If they have there’s too much IgM, they can actually make the blood a little thick, and that can cause a little bit of problems with the circulation, specifically in the eyes, for example. Some patients have blurred vision. Some patients have nosebleeds or headaches, right, with all that hyperviscosity, which means the blood is too thick. In some other patients, we have nerve damage. You know, they can have numbness in their toes, and then that increases into the – progresses, extends into the feet, into the shins, into the knees and then the fingers.
And so, that happens over years sometimes. Some patients can have enlargement of lymph nodes in their necks and in the axillary areas or in the inguinal areas, or even enlargement of organs, the spleen and liver and things like that. So, when we think about the clinical manifestations of Waldenstrom’s, it varies, very diverse. But I would say most patients would have anemia. I think that’s probably the most important aspect of it.