[Multibilly]

Beta-2 microglobulin in smoldering multiple myeloma

by Multibilly on Mon May 11, 2015 7:55 pm

In case those of you with smoldering myeloma haven't seen this study on the impact of beta 2 micro­globulin (B2M) on risk-of-progression, I thought you might find it to be interesting (see reference and abstract below).

For those of you unfamiliar with B2M, it is used as a general measure of the amount of cancer (tumor burden) in patients with various blood cancers, such as multiple myeloma and lym­pho­ma.

I happen to track my B2M and you can find my B2M history graphed below. Given my B2M level of 2510 ug/L (2.51 mg/L), I wonder if I truly am at a higher risk for progression? Has any­one else had a B2M at this level and stayed smoldering for an extended amount of time? Has your B2M changed much while you were smoldering?

I also wonder how many specialists subscribe to the assertions made in this study, since one doesn't typically hear much about B2M and smoldering multiple myeloma?

Reference:

D Rossi et al, "Beta-2-microglobulin is an independent predictor of progression in asymptomatic multiple myeloma," Cancer, May 2010 (full text of article)

Abstract:

Background: Although serum beta-2 microglobulin (B2M) represents a key variable for symp­to­matic multiple myeloma (M​M) prognostication, its role in predicting the risk of progression of asymptomatic M​M to symptomatic disease has not been explored.

Methods: This study was bases on a consecutive series of 148 patients with asymp­tom­atic M​M and explored the cumulative probability of progression to symptomatic M​M as the primary endpoint.

Results: In univariate analysis, a serum B2M level >2.5 mg/L was associated with an increased probability of disease progression (5-year risk, 64.5%; P < .001) along with serum monoclonal component (sMC) (P < .001), urinary monoclonal component (uMC) (P < .001), and bone marrow plasma cells (BMPCs) (P < .001). In multivariate analysis, serum B2M was selected as an independent predictor of progression (hazard ratio, 3.30; P = .002). Serum B2M was combined with sMC, uMC, and BMPC to create a risk-stratification model based on 4 groups with different risk of progression: very low (5-year risk, 0%), low-intermediate (5-year risk, 19.6%), high-intermediate (5-year risk, 60.7%), and high (5-year risk, 80.7%). The model that included serum B2M along with sMC, uMC, and BMPC was able to predict disease progression better than the model that was based on sMC, uMC, and BMPC without serum B2M (C statistics, 0.760 vs 0.726).

Conclusions: The current results indicated that 1) serum B2M is an independent pre­dictor of asymptomatic multiple myeloma progression, and 2) serum B2M adds prog­nos­tic information when combined with the most widely used prognosticators of asymp­tom­atic multiple myeloma progression.

B2M.png (7.65 KiB) Viewed 2666 times

[Dr. Jatin Shah]

Re: Beta-2 microglobulin in smoldering multiple myeloma

by Dr. Jatin Shah on Mon May 11, 2015 10:32 pm

This is an interesting article. However, these findings have not been further validated, and we have other good tools to predict progression.

In addition, the article does not apply to your situation, as it only looked at B2M at the time of diagnosis. It did not look at serial changes in patients' B2M levels, or B2M several years after diagnosis.

Also, B2M levels can be affected by many things, including infection and renal dysfunction, and thus are not a marker of progression.

For all the reasons I just mentioned, I don't think the changes in your B2M are relevant to your risk of progression.

Myeloma specialists generally do not use B2M to assess whether or not smoldering myeloma is showing signs of progression. Instead, we look at baseline numbers and change over time in the patient's paraprotein to define evolving disease and determine if progression to symp­tom­atic disease is likely in the near term.

[Multibilly]

Re: Beta-2 microglobulin in smoldering multiple myeloma

by Multibilly on Tue May 12, 2015 7:17 am

As always, many thanks for your comments Dr. Shah! We all greatly appreciate the time the Beacon advisors take to comment on various posts on this forum.

[smarty]

Re: Beta-2 microglobulin in smoldering multiple myeloma

by smarty on Tue May 12, 2015 1:01 pm

I'm confused, is B2M same as M-spike?

[Carolee]

Re: Beta-2 microglobulin in smoldering multiple myeloma

by Carolee on Tue May 12, 2015 6:25 pm

I noticed your level of beta-2 microglobulin and was interested in the level.

I have MGUS, but when I was first being monitored, my B2M reached 2.45 mg/L. I read about B2M and saw a rheumatologist. After testing, I was put on an immunosuppresent and my B2M swiftly dropped. So my beta-2 microglobulin rose because of a lot of inflammation due to autoimmune diseases.