[blair77]

Problems with Clonosight MRD testing

by blair77 on Thu Jan 15, 2015 1:10 am

So we have been waiting 4 months for the results of Clonosight MRD testing. This involves sequencing the DNA from the cancer cells in the bone marrow at diagnosis and then "looking" for the cancer in a recent BMB post treatment.

However, the Clonosight lab has rejected 2 different samples from the original BMB in April 2013, stating there wasn't enough "cancer" to sequence.

How can this be possible? Does anyone have experience with this test?

[Mark11]

Re: Problems with Clonosight MRD testing

by Mark11 on Thu Jan 15, 2015 11:17 am

Hi Blair77,

I doubt a lot of patients have used this test. The test cannot be set up for around 10% patients. That is a downside to molecular testing methods. They require a good sample from diag­nosis. Clonosight / Lymphosight 90% plus applicability is higher than ASO-PCR (around 75%), which is the other form of molecular testing used currently.

"The applicability of deep sequencing was 91%"; from

J Martinez-Lopez et al, "Prognostic value of deep sequencing method for minimal residual disease detection in multiple myeloma," Blood, May 15, 2014 (full text at PubMed).

Also, related Beacon news article:

"Minimal Residual Disease, Deep Sequencing, And Prognosis In Multiple Myeloma," The Myeloma Beacon, Apr 8, 2014.

You could use the flow method. It is not quite as sensitive, but does not require a good sample from diagnosis.

Mark