In a population-based cohort study reported in the Journal of the National Cancer Institute, Su-Hsin Chang, PhD, of the Washington University School of Medicine, and colleagues found that overweight and obesity were associated with an increased risk of transformation of monoclonal gammopathy of undetermined significance to multiple myeloma. Black race was also associated with an increased risk.
The study involved a Veterans Health Administration cohort of 7,878 patients diagnosed with monoclonal gammopathy of undetermined significance between October 1999 and December 2009, with follow-up through August 2013. Among all patients, median age at diagnosis of monoclonal gammopathy of undetermined significance was 72 years, 97% were male, 39.8% were overweight (body mass index = 25–29.9 kg/m2) and 33.8% were obese (≥ 30 kg/m2), and 64.1% were white and 24.5% were black.
Risk Factors
Median follow-up was 68 months. During follow-up, 329 patients (4.2%) progressed to multiple myeloma, including 72 normal-weight patients (3.5%), 144 overweight patients (4.6%), and 113 obese patients (4.3%). In multivariable analysis, overweight (hazard ratio [HR] = 1.55, P = .003) and obesity (HR = 1.98, P < .001) were associated with an increased risk of transformation of monoclonal gammopathy of undetermined significance to myeloma, as was black race (HR =1.98, P < .001). Higher Charlson comorbidity score (excluding diabetes) was associated with a lower risk (HR = 0.89, P < .001), as was serum creatinine level ≥ 1.5 mg/dL (HR = 0.61, P = .001).
The investigators concluded: “Obesity and black race are risk factors for transformation of [monoclonal gammopathy of undetermined significance] to [multiple myeloma]. Future clinical trials should examine whether weight loss is a way to prevent the progression to [multiple myeloma] in [monoclonal gammopathy of undetermined significance] patients.”
The study was supported by the Foundation for Barnes-Jewish Hospital, Siteman Cancer Center, the National Institutes of Health grants, the Agency for Healthcare Research and Quality, and the American Cancer Society. ■
