First-degree relatives of patients with multiple myeloma (MM) are at a higher risk for monoclonal gammopathy of undetermined significance (MGUS) a recent study showed — and this risk was independent of the proband’s age at diagnosis.1 The results were published online September 10, 2018, in Leukemia.
Study researchers recruited a total of 430 probands (400 MM and 30 smoldering MM) and 1179 of their first-degree relatives for a study at the Mayo Clinic in Rochester, Minnesota between 2005 and 2015. Only first-degree relatives ages 40 years and older were eligible. Most probands were Caucasian (97.0%) and male (56.0%) and between the ages of 50 and 79 years (85.8%). Most first-degree relatives were female (58.7%) and were a sibling of the proband (62.8%).
In total, 75 of the 1179 first-degree relatives were diagnosed with MGUS, yielding an age- and sex-adjusted prevalence of 5.8% (95% CI, 4.5-7.2). First-degree relatives of probands had a 2.4-fold higher risk of MGUS (95% CI, 1.9-2.9) than the expected rates.
The difference in risk was evaluated by proband characteristics, including age at diagnosis, gender, isotype, IgH translocation, and trisomy. No differences in familial risk for the aforementioned characteristics reached statistical significance.
Study authors also found no survival difference at 15 years follow-up between MM probands who had a first-degree relative with MGUS and probands who had a first-degree relative without MGUS (HR = 0.93, 95% CI, 0.64-1.35, P= 0.7).
“This study confirms first-degree relatives of MM cases have a significantly higher risk of MGUS compared to the general population, regardless of age, gender, or tumor characteristics,” the study authors wrote. “In selected situations, such as multiple affected first-degree relatives, screening of first-degree relatives of MM cases could be considered for follow-up and prevention strategies.”
- Clay-Gilmour AI, Kumar S, Rajkumar SV, et al. Risk of MGUS in relatives of multiple myeloma cases by clinical and tumor characteristics [published online September 10, 2018]. Leukemia. doi: 10.1038/s41375-018-0246-2