[Cheryl G]

Update on Mayo MGUS & progression risk statistics

by Cheryl G on Wed Jan 17, 2018 7:48 pm

Hi everyone,

The Mayo Clinic has published an update to its statistics about MGUS and the risk of progression from MGUS to multiple myeloma and other related diseases.

Across all MGUS patients in the study, the risk of progression from MGUS to multiple myeloma (and related diseases) was:

10% at 10 years
18% at 20 years
28% at 30 years
36% at 35 years
36% at 40 years.

The researchers used two risk factors to identify MGUS patients at a higher risk of progression. Those risk factors were:

1. An abnormal (outside the normal range) kappa-lambda serum free light chain ratio
2. An M-spike of 1.5 g/dL or higher

Among non-IgM (mainly IgG and IgA) MGUS patients, the risk of progressing within 20 years was:

30% among those who both risk factors
20% among those who had one of the two risk factors
7% among those who had neither risk factor.

Here's a link to the study:

"Long-Term Follow-up of Monoclonal Gammopathy of Undetermined Significance"
http://www.nejm.org/doi/full/10.1056/NEJMoa1709974

And here's the abstract:

Background - Monoclonal gammopathy of undetermined significance (MGUS) occurs in approximately 3% of persons 50 years of age or older.

Methods - We studied 1384 patients who were residing in southeastern Minnesota and in whom MGUS was diagnosed at the Mayo Clinic in the period from 1960 through 1994; the median follow-up was 34.1 years (range, 0.0 to 43.6). The primary end point was progression to multiple myeloma or another plasma-cell or lymphoid disorder.

Results - During 14,130 person-years of follow-up, MGUS progressed in 147 patients (11%), a rate that was 6.5 times (95% confidence interval [CI], 5.5 to 7.7) as high as the rate in the control population. The risk of progression without accounting for death due to competing causes was 10% at 10 years, 18% at 20 years, 28% at 30 years, 36% at 35 years, and 36% at 40 years. Among patients with IgM MGUS, the presence of two adverse risk factors — namely, an abnormal serum free light-chain ratio (ratio of kappa to lambda free light chains) and a high serum monoclonal protein (M protein) level (≥1.5 g per deciliter) — was associated with a risk of progression at 20 years of 55%, as compared with 41% among patients who had one adverse risk factor and 19% among patients who had neither risk factor. Among patients with non-IgM MGUS, the risk of progression at 20 years was 30% among those who had the two risk factors, 20% among those who had one risk factor, and 7% among those who had neither risk factor. Patients with MGUS had shorter survival than was expected in the control population of Minnesota residents of matched age and sex (median, 8.1 vs. 12.4 years; P<0.001).

Conclusions - Significant differences were noted in the risk of progression between patients with IgM MGUS and those with non-IgM MGUS. Overall survival was shorter among patients with MGUS than was expected in a matched control population. (Funded by the National Cancer Institute.)

[Ruben_1980]

Re: Update on Mayo MGUS & progression risk statistics

by Ruben_1980 on Fri Jan 19, 2018 6:07 pm

Thank you for sharing this, Cheryl.

Do you know if there is anything in the article about light chain MGUS?

Best regards,
Ruben

[Cheryl G]

Re: Update on Mayo MGUS & progression risk statistics

by Cheryl G on Tue Jan 23, 2018 12:40 pm

Hi Ruben,

I don't have access to the full text of the article, so I can't answer your question definitively. However, I suspect there is not much new in the article about light chain MGUS, since light chain MGUS is a relatively new diagnosis. I believe the most frequently cited study about light chain MGUS (by Dr. Dispenzieri and her colleagues, and published in 2010 in the Lancet) is based on data that started being collected in 1995, some 20 years later than the first data mentioned in the above article.

[Ruben_1980]

Re: Update on Mayo MGUS & progression risk statistics

by Ruben_1980 on Tue Jan 23, 2018 5:51 pm

Thanks for your reply, Cheryl! It's so nice that you take the time to respond

Best wishes,
Ruben

[Taco Cat]

Re: Update on Mayo MGUS & progression risk statistics

by Taco Cat on Tue May 01, 2018 4:25 pm

Hi there,

Many thanks to everyone on the group for your very useful posts.

I'm in the process of being diagnosed right now and this is all very overwhelming as I'm only 43 and have 5 kids I need to be around for. Anyway, my serum free light chain kappa-lambda ratio is 0.1185 because my lambda free light chains are high at 23.2 mg/dL. There has been a monoclonal gammopathy of IgA lambda type detected twice now in two recent immunofixations. I also picked up a new monoclonal lambda in the last IFE. There is no detectable M-spike, but I've read that often is the case with IgA, so it doesn't mean much (my IgA levels are 597 mg/dL on the first test and 647 mg/dL on the most recent test two months later).

Of course, I'm reading everything I can get my hands on about MGUS and myeloma. The most relevant study I had found charted out the risk progression of MGUS with an abnormal serum free light chain ratio and it put the risk at 3% per year.

Is that really correct, or even possible? It seems so much higher than the standard baseline risk of 1% per year I see everywhere else. I'd gladly take 1% over 3% any day.

Here is the link to where I found it:

Rajkumar, SV, et al., "Serum free light chain ratio is an independent risk factor for progression in monoclonal gammopathy of undetermined significance," Blood, Aug 1, 2005 (full text of article)

It is in the last column of Table 2.

Sincere thanks in advance for any comments or opinions.