Can anyone help me with an explanation here:
The difference between:
A) Complete Response [CR], and
B) Stringent Complete Response [sCR]?
Are they measured with the same methods and what is the difference / definition?
And how are they compared having no "minimal residual disease" (MRD) -- that is, being "minimal residual disease negative" (MRD-)?
How is minimal residue disease measured?
Best regards,
Lev
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Lev - Name: Lev
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: June 2014
- Age at diagnosis: 57
Re: Response definitions and minimal residual disease
See Table 1 in this article for a thorough description of all myeloma response definitions (not including minimal residual disease):
SV Rajkumar, "Consensus recommendations for the uniform reporting of clinical trials: report of the International Myeloma Workshop Consensus Panel 1", Blood, May 2011 (PDF with full text of article)
To summarise:
Complete response =
No M-spike on serum protein electrophoresis +
No monoclonal protein found on serum immunofixation electrophoresis +
No extramedullary plasmacytomas +
Less than 5 percent plasma cells in the bone marrow
Stringent complete response =
All conditions for a complete response +
Normal serum free light chain ratio +
No clonal plasma cells in the bone marrow based on 2- or 4-color flow cytometry
Minimal residual disease testing does not involve M-spikes or free light chain ratios. Instead, it is based on very sensitive testing of the bone marrow to determine if any clonal plasma cells are still present in the marrow, and/or sensitive imaging-based testing to assess whether clonal plasma cells are present in the bone marrow.
There are different methods of testing for minimal residual disease, and there has not been for many years an agreed-upon definition of "minimal residual disease negative" status. A definition has been proposed by the IMWG, as I understand it, but I am not sure if it has been published in a medical journal yet.
One thing that can be confusing about MRD testing is that a patient can be found to be MRD negative, yet not have achieved a complete response. This is because of the different ways the different responses are defined and, for example, the lags that occur in how the monoclonal protein in the blood changes as myeloma responds to treatment.
Search "residual" in the forum search box for other discussions of MRD in the forum; some of them may help you more than what I've written.
Cheers!
SV Rajkumar, "Consensus recommendations for the uniform reporting of clinical trials: report of the International Myeloma Workshop Consensus Panel 1", Blood, May 2011 (PDF with full text of article)
To summarise:
Complete response =
No M-spike on serum protein electrophoresis +
No monoclonal protein found on serum immunofixation electrophoresis +
No extramedullary plasmacytomas +
Less than 5 percent plasma cells in the bone marrow
Stringent complete response =
All conditions for a complete response +
Normal serum free light chain ratio +
No clonal plasma cells in the bone marrow based on 2- or 4-color flow cytometry
Minimal residual disease testing does not involve M-spikes or free light chain ratios. Instead, it is based on very sensitive testing of the bone marrow to determine if any clonal plasma cells are still present in the marrow, and/or sensitive imaging-based testing to assess whether clonal plasma cells are present in the bone marrow.
There are different methods of testing for minimal residual disease, and there has not been for many years an agreed-upon definition of "minimal residual disease negative" status. A definition has been proposed by the IMWG, as I understand it, but I am not sure if it has been published in a medical journal yet.
One thing that can be confusing about MRD testing is that a patient can be found to be MRD negative, yet not have achieved a complete response. This is because of the different ways the different responses are defined and, for example, the lags that occur in how the monoclonal protein in the blood changes as myeloma responds to treatment.
Search "residual" in the forum search box for other discussions of MRD in the forum; some of them may help you more than what I've written.
Cheers!
Re: Response definitions and minimal residual disease
Hi Ian,
Thank you for your very helpful answer!
Best regards
Lev
Thank you for your very helpful answer!
Best regards
Lev
-
Lev - Name: Lev
- Who do you know with myeloma?: Me
- When were you/they diagnosed?: June 2014
- Age at diagnosis: 57
3 posts
• Page 1 of 1