How often will I need a bone marrow biopsy?

So, this is a highly controversial topic, and I will admit there's a spectrum and I am all the way on one end of the spectrum. So, it needs to be done at diagnosis. And the question is, when does it need to be done again? There are options. So, it actually turns out that in the United States, the majority of myeloma patients only get one bone marrow biopsy at the time of diagnosis. Because right now, even though we get some insight into how we might adjust treatment, most of our treatments in subsequent stages don't really depend upon the bone marrow. That being said, we're starting to understand that if you do it at the time of a deep remission, we can then analyze it for what we call MRD, or minimal residual disease. So, sometimes we'll do it when someone has achieved that initial deep remission to say, all right, your remission is really deep. Should we do a transplant or not? And then sometimes we'll do it once a year thereafter to say, all right, you're on maintenance. Have you maintained this deep remission so long that you'll probably do just as well continuing or not? But again, there are other reasons. So for example, if a patient automatically develops low blood counts, I might do a bone marrow biopsy because there are three big reasons why you can have low blood counts that you don't expect. One is that the myeloma is not making as much of that M-spike or light chain, and we call that non-secretory. Maybe it's growing in the bone marrow and crowding out the healthy cells, even though it's not making a rising M-spike. Two, the treatment we give sometimes lower the counts. So it could be that you have some marrow fatigue or marrow weakness from all the treatment and we need to back off. And the third is that there are other bone marrow disorders like myelodysplastic syndrome that you can get from the treatment. So for me, I only do a bone marrow in my clinic where it is going to impact a treatment decision. Are we going to do A or B? If we need a marrow, we'll do it. Is there a reason we can't explain your blood counts that might change how we approach things? Then I will do it. I tend not to do yearly marrows just because, because for most of the part, it's not going to change what we do. But some physicians choose to do yearly marrows to keep tabs on things just to know more about the whole situation.