Hello,
I was wondering the same sort of thing, whether it was possible to have no chromosome abnormalities, but then to acquire them upon relapse, and also whether treatment can reverse chromosomal abnormalities. Thanks.
Forums
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PattiM - Name: Patti
- Who do you know with myeloma?: myself
- When were you/they diagnosed?: April 2015
- Age at diagnosis: 47
Re: Can cytogenetics (chromosomal abnormalities) change?
Hi Lizzie,
What you say is essentially true.
Think of it this way. DNA makes up genes. Genes make up chromosomes. In a perfect person, each cell of their body has the same, identical chromosomes, along with the same underlying genes that makes up these chromosomes. What makes one type of cell different from another is how each of the many genes in those cells are expressed (turned on or turned off).
In myeloma patients, it's a combination of how certain chromosomes present in a portion of their plasma cells may be mutated (i.e. having an extra copy of a chromosome, missing a part of chromosome, having parts of two different chromosomes being swapped, etc) that cause us so many problems.
Those patients can also have genes in a portion of their plasma cells be erroneously expressed (turned on) or not expressed (turned off), which is why some facilities now do "gene expression profiling" of myeloma patients. And, to complicate things further, you can have different lines of plasma cells with different chromosomal mutations and gene expression profiles, and all of these "clonal lines" are continually evolving and competing to dominate and take over the entire plasma cell line.
Here's another way to think of it. If the mutations found in the cancerous plasma cells showed up in every cell, then we could simply avoid bone marrow biopsies and just put some cells from our spit through the various bone marrow biopsy tests. When you have a bone marrow biopsy or undergo gene expression profiling, the plasma cells are first identified and separated from the rest of the cells in the biopsy sample before all the various tests (i.e. FISH, karyotyping, gene expression profiling, etc) are conducted.
Lastly, I don't believe that treatment necessarily "reverses" and corrects these mutations, but it does hopefully target and wipe out specific clonal lines of plasma cells that contain these mutations.
What you say is essentially true.
Think of it this way. DNA makes up genes. Genes make up chromosomes. In a perfect person, each cell of their body has the same, identical chromosomes, along with the same underlying genes that makes up these chromosomes. What makes one type of cell different from another is how each of the many genes in those cells are expressed (turned on or turned off).
In myeloma patients, it's a combination of how certain chromosomes present in a portion of their plasma cells may be mutated (i.e. having an extra copy of a chromosome, missing a part of chromosome, having parts of two different chromosomes being swapped, etc) that cause us so many problems.
Those patients can also have genes in a portion of their plasma cells be erroneously expressed (turned on) or not expressed (turned off), which is why some facilities now do "gene expression profiling" of myeloma patients. And, to complicate things further, you can have different lines of plasma cells with different chromosomal mutations and gene expression profiles, and all of these "clonal lines" are continually evolving and competing to dominate and take over the entire plasma cell line.
Here's another way to think of it. If the mutations found in the cancerous plasma cells showed up in every cell, then we could simply avoid bone marrow biopsies and just put some cells from our spit through the various bone marrow biopsy tests. When you have a bone marrow biopsy or undergo gene expression profiling, the plasma cells are first identified and separated from the rest of the cells in the biopsy sample before all the various tests (i.e. FISH, karyotyping, gene expression profiling, etc) are conducted.
Lastly, I don't believe that treatment necessarily "reverses" and corrects these mutations, but it does hopefully target and wipe out specific clonal lines of plasma cells that contain these mutations.
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Multibilly - Name: Multibilly
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: Smoldering, Nov, 2012
Re: Can cytogenetics (chromosomal abnormalities) change?
Hi Pattie,
I have an example of what Multibilly describes. After 12 months or so of Revlimid, Velcade, and dexamethasone, my M-spike had plateaued and I was worn out by side effects. (My hematologist oncologist uses the M-spike as our primary marker.) So we switched to Velcade alone and after many months of very small monthly increases on my M-spike, it began to go up rapidly.
Before we started on new treatment for the refractory disease, refractory chemotherapy (i.e., my second treatment regimen), my oncologist ordered a bone marrow biopsy specifically to check whether or not my myeloma with so far normal gene expressions had mutated into a more aggressive strain of the disease. This might enable him to more accurately choose the next treatment for me.
So, yes, cytogenetics can mutate during treatment or relapse. I believe that treatment does not change our chromosomes.
Multibilly, thanks for all of your help!
I have an example of what Multibilly describes. After 12 months or so of Revlimid, Velcade, and dexamethasone, my M-spike had plateaued and I was worn out by side effects. (My hematologist oncologist uses the M-spike as our primary marker.) So we switched to Velcade alone and after many months of very small monthly increases on my M-spike, it began to go up rapidly.
Before we started on new treatment for the refractory disease, refractory chemotherapy (i.e., my second treatment regimen), my oncologist ordered a bone marrow biopsy specifically to check whether or not my myeloma with so far normal gene expressions had mutated into a more aggressive strain of the disease. This might enable him to more accurately choose the next treatment for me.
So, yes, cytogenetics can mutate during treatment or relapse. I believe that treatment does not change our chromosomes.
Multibilly, thanks for all of your help!
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Hummingbird
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