Posted: Monday, April 24, 2023
Lawrence W. Liu, MD, of City of Hope Comprehensive Cancer Center, Duarte, California, and colleagues conducted a retrospective study evaluating racial disparities among U.S. veterans on metformin for diabetes who are at risk of monoclonal gammopathy of undetermined significance (MGUS) progression to multiple myeloma. Presented during the American Association for Cancer Research (AACR) Annual Meeting 2023 (Abstract 1960/1), the results of this study suggest that although White patients experienced a reduced risk of progression to multiple myeloma, Black patients did not.
The investigators focused on 4,268 Black (26.2%) and White (36.2%) patients from the Veterans Health Administration diagnosed with MGUS. Eligible participants included those with diabetes mellitus who were treated with metformin for at least 4 years after diagnosis of MGUS and before the development of multiple myeloma.
Metformin use status was used to stratify cumulative incidence functions, and Gray’s test detected differences between the two functions. A multivariable adjusted hazard ratio using a Fine-Grey subdistribution model was used to determine the correlation between metformin use and disease progression.
A statistically significant difference in cumulative incidence functions was observed, demonstrating a lower progression rate to multiple myeloma for metformin users (P = .04). Multivariable analysis also revealed a statistically significant reduction in disease progression with metformin use in the overall cohort, with a multivariable adjusted hazard ratio (aHR) of 0.79. Although there was a significant reduction in disease progression rate among White patients who used metformin (aHR = 0.73), this did not appear to hold true for Black patients (aHR = 0.90).
Disclosure: The study authors reported no conflicts of interest.