[Grant]

No beta 2 microglobulin test - why?

by Grant on Wed Oct 22, 2014 9:14 am

Is there a reason why my hematologist would not order a beta 2 microglobulin test for my multiple myeloma? It seems from everything I have read that this is the primary test used to determine staging of myeloma?

[Cheryl G]

Re: No beta 2 microglobulin test - why?

by Cheryl G on Wed Oct 22, 2014 3:04 pm

Hi Grant,

Beta 2 microglobulin and albumin levels at diagnosis are used in the International Staging System (ISS) for myeloma. However, neither of those variables are used in the older Durie-Salmon staging system. Your hematologist may be more familiar with the Durie-Salmon system.

There is a study from a while ago, by the way, that suggests that Durie-Salmon system (DSS) may be just as good, if not better, than the ISS at predicting progression-free survival (PFS) and overall survival (OS) in myeloma patients undergoing a stem cell transplant.

PN Hari et al, "Is the international staging system superior to the Durie–Salmon staging system? A comparison in multiple myeloma patients undergoing autologous transplant," Leukemia (2009) 23, 1528-1534 (full text)

Although both systems were predictive of PFS and OS, the DSS was superior in formal statistical comparison using Brier score. However, neither system was strongly predictive of outcomes, indicating the need for newer schemes incorporating other prognostic markers."

This link has the details of the two staging systems:

http://www.lls.org/diseaseinformation/myeloma/myelomastaging/

Although it's still common for myeloma patients to be staged at diagnosis, the weakness of the different staging systems is one of the main reasons that myeloma specialists prefer to focus on classifying patients into different risk categories, using systems like the one developed by the Mayo Clinic or the one developed by the International Myeloma Working Group:

http://msmart.org/newly%20diagnosed%20myeloma.pdf (see esp. page 4)

"IMWG Experts Publish Consensus Risk Classification For Multiple Myeloma," The Myeloma Beacon, Sep 13, 2013.

Hope this clarifies things a bit for you. Good luck!

[Grant]

Re: No beta 2 microglobulin test - why?

by Grant on Thu Oct 23, 2014 2:32 am

Thanks Cheryl, that is super useful!