[Grethe]

Is complete response possible with light chain myeloma?

by Grethe on Wed Aug 28, 2013 3:00 pm

My husband has light chain myeloma, and thus he only has light chains to measure and monitor. When he was diagnosed last year, his kappa light chains were appx 5400 and his lambda light chains were 0.1. Induction treatment reduced the kappa light chains to appx 1400, and then ASCT reduced it further to 386. Three months after ASCT he started consolidation treatment with Revlimid (25 mg) and Dex. After two cycles of this we were told today that his light chains are now "in the normal range". We are very happy and fortunate! And we are keen to get advice on what to do now. Should my husband continue with one more cycle of the consolidation to get to 0? There is so much talk about a complete response and getting to 0, but for light chains there is a apparently then a normal range which is above 0. Is it even possible to get to 0 when you have only light chains?

The IMWG response evaluation criteria for complete response is “Negative immunofixation on the serum and urine and disappearance of any soft tissue plasmacytomas and < 5% plasma cells in bone marrow.” This again leads me to ask whether negative immunofixation is possible to achieve when you only have light chains – since there is a normal range for light chains?

Two months ago my husband BMP showed appx 5% plasma cells. A new one hasn’t been taken after the two cycles of consolidation treatment. He still has not had a FISH test or anything to determine his risk category.

Looking forward to hearing from someone out there on this. It's such a privilege to have a community to reach out to in this way. Wishing you all the best.

Grethe

[dnalex]

Re: Is complete response possible with light chain myeloma?

by dnalex on Wed Aug 28, 2013 3:46 pm

Hi Grethe,

A complete response with light chain only myeloma patients is definitely possible, but the determination of that is not based solely on kappa and lambda levels/ratios in the blood. Actually, a complete response is not determined by just this measurement with any type of myeloma. Even with a complete response, you should only expect kappa and lambda to go back to normal range, with normal ratios, because there are normal B cells producing these paraproteins.

In this case, PET, MRI, and bone marrow determinations will need to be done, and possibly even looking at minimal residual disease.