Association and Prognostic Significance of Comorbidities in Individuals With MGUS

Introduction: Monoclonal gammopathy of undetermined significance (MGUS) is a benign precursor of multiple myeloma, but little is known about the role of comorbidities in progression. Materials and Methods: A retrospective review of medical records of patients with MGUS (n = 150) or a negative MGUS workup (n = 96) seen at a comprehensive cancer center between 2007 and 2023 was performed. Charlson Comorbidity Index (CCI) scores, descriptive characteristics, and overall (OS) and progression-free (PFS) survival were abstracted. Group differences (MGUS vs negative) in CCI and other characteristics were tested with Student's t-tests and Pearson's chi-square tests. Univariate and multivariate Cox proportional hazard models were used to model the association between CCI and OS and PFS in patients with MGUS. Results: Patients with MGUS had a higher mean CCI (P = .01) and prevalence of diabetes mellitus with end-organ damage (P < .05) and solid tumors (P = .01) than patients with a negative MGUS workup. Each additional CCI point was associated with shorter OS (HR 1.50, P< .01) and PFS (HR 1.25, P < .01). Results were not confounded by age, body mass index, or sex. Conclusions: Our study suggests that comorbidities are relevant to risk of MGUS and that prevention and management of comorbidities in patients with MGUS is indicated and may be associated with improved outcomes.