Multiple myeloma is the third most common type of blood cancer, with an estimated 30,000 new cases diagnosed annually in the United States. It develops more frequently after age 60 and is almost always preceded by a benign blood condition called monoclonal gammopathy of undetermined significance, known as MGUS, in which abnormal plasma cells produce excess copies of an antibody protein without causing symptoms. Because MGUS rarely produces noticeable signs, it frequently goes undiagnosed until progression to multiple myeloma is already underway. A new study from Washington University School of Medicine in St. Louis, published in the Journal of the National Cancer Institute, now identifies excess body weight as a significant and modifiable risk factor for that progression.
How Obesity Accelerates the Path to Multiple Myeloma
The research team analyzed data from a U.S. Department of Veterans Affairs database, identifying 7,878 patients diagnosed with MGUS between October 1999 and December 2009. Among these patients, 39.8 percent were overweight and 33.8 percent were obese. The researchers then tracked progression to multiple myeloma over a median follow up period of approximately five to six years.
The results showed a clear and statistically significant relationship between body weight and multiple myeloma risk. Among normal weight patients, 3.5 percent developed multiple myeloma. Among overweight patients, 4.6 percent progressed, representing a 55 percent higher risk compared to those at normal weight. Among obese patients, 4.3 percent progressed, representing a 98 percent higher risk, nearly double that of normal weight patients. For patients already diagnosed with MGUS, maintaining a healthy weight may represent one of the most accessible interventions available to reduce the risk of progressing to multiple myeloma.
What MGUS Is and Why It Matters for Multiple Myeloma Prevention
MGUS is caused by elevated levels of M protein, an abnormal antibody, found in approximately 3 percent of people over age 50. By itself, the condition does not cause symptoms and does not typically warrant treatment. Diagnosis usually occurs incidentally, during testing ordered for other conditions. Despite its benign appearance, MGUS is the established precursor to multiple myeloma, making it a critical window for monitoring and intervention.
As study first author Su Hsin Chang, PhD, of Washington University noted, regular medical check ups can help physicians track whether MGUS is progressing toward multiple myeloma or other disorders, even though the study does not directly advocate population wide MGUS screening. For patients who have been diagnosed with MGUS, the finding that obesity nearly doubles progression risk provides a compelling reason to prioritize weight management as part of ongoing disease monitoring.
Racial Disparities in Multiple Myeloma Progression
The study also identified a racial disparity in progression risk. African American men in the MGUS cohort were more likely than their white counterparts to progress to multiple myeloma. This finding is consistent with broader patterns in multiple myeloma epidemiology, where Black patients have approximately twice the incidence rate of white patients and are diagnosed at younger ages on average.
Chang emphasized that for Black patients diagnosed with MGUS, close monitoring of disease progression should be prioritized alongside healthy weight maintenance. These findings reinforce the importance of ensuring that Black and other minority patients have equitable access to hematology follow up care and are not lost to monitoring after an incidental MGUS diagnosis.
What Comes Next in Multiple Myeloma and Obesity Research
The Washington University team plans to investigate whether intentional weight loss is inversely associated with multiple myeloma progression in MGUS patients, and how weight change over time influences disease trajectory. These future studies will be critical for determining whether weight management recommendations can be translated into concrete clinical guidance for MGUS patients.
Because excess weight is a modifiable risk factor, unlike age or genetics, the researchers expressed hope that these findings will encourage early intervention strategies in the MGUS population. If confirmed in clinical trials, weight management could become a standard component of MGUS management alongside regular monitoring for serological changes.
To read more about hematology and oncology research, visit the FOMAT blog. FOMAT conducts multiple myeloma and hematology clinical trials at sites across the United States. To learn more about active studies, visit FOMAT’s patient studies page.
For the full source, see the original article at Bioscience Technology.