- Monoclonal gammopathy of unknown significance (MGUS) is a benign precancerous condition, often diagnosed incidentally. It is usually asymptomatic.
- MGUS is a disorder of plasma cells, which produce an abnormal antibody protein termed M protein, with elevated levels in the blood and can progress to myeloma, a cancer.
- According to statistics, the risk of progression to myeloma is about 1 percent per year.
- Present study has identified an increased risk of progression to myeloma in obese, and overweight MGUS patients.
- Weight loss and maintaining a healthy weight might reduce risk of MGUS progression to multiple myeloma.
Risk of progression to multiple myeloma is higher in overweight and obese MGUS patients, according to a recent study conducted by researchers at Washington University School of Medicine in St. Louis.
Aim of the Study
‘Maintaining a healthy weight in monoclonal gammopathy of unknown significance (MGUS) patients reduces risk of progression to multiple myeloma.’
It has been long known that obesity and being overweight are associated with an increased risk of multiple myeloma, a plasma cell cancer occurring in persons over 60 years of age.
What the study authors wished to assess was whether the same risk factors contributed to myeloma progression in patients who were diagnosed with MGUS
, a precancerous condition, though in itself benign.
About Monoclonal Gammopathy of Unknown Significance (MGUS)
MGUS is a disorder of plasma cells, wherein they secrete an abnormal protein termed M protein, whose levels in blood are elevated and can be detected by blood tests. It is benign but may progress to multiple myeloma
, a cancerous condition.
MGUS is diagnosed incidentally and is asymptomatic. The exact cause of MGUS remains unknown. At present, patients diagnosed with MGUS undergo regular follow ups and monitoring of their M protein levels, with doctors following a 'wait and watch policy'.
Details and Findings of the Study
Data from a U.S. Department of Veterans Affairs database were analysed, that identified 7,878 patients
, mostly men, who had been diagnosed with MGUS from October 1999 to December 2009.
Of these, 33.8 percent were found to be obese and 39.8 percent were overweight, who were then tracked to determine the risk of progression to myeloma. The results were as follows
- 4.6 percent of patients who were overweight (tracked for an average of 5.75 years) and 4.3 percent of patients who were obese (tracked for a median of 5.9 years) progressed to multiple myeloma, in comparison with 3.5 percent of normal weight patients (tracked for a median of 5.2 years) - a difference that would be significant statistically.
- Overweight MGUS patients had a 55 percent higher risk of progression, and obese MGUS patients had 98 percent higher risk of progression when compared to normal weight patients.
- Interestingly, the risk of progression was higher in African-Americans compared to their Caucasian counterparts.
"The diagnosis (of MGUS) is usually by accident, often driven by tests performed for the diagnosis or management of other conditions," said Chang, the lead author of the study. "Although our study does not directly suggest screening for MGUS, regular check-ups can help physicians monitor whether MGUS is progressing to other disorders, including multiple myeloma."
Multiple Myeloma in Brief
Multiple myeloma is a plasma cell cancer that can be treated but is generally considered incurable. It is the third major type of blood cancer, and characterized by anemia, bone pain, infections, kidney failure, and neurological symptoms.
Remissions may be obtained with steroids, chemotherapy and stem cell transplant.
The American Cancer Society predicts that more than 30,000 new cases will be diagnosed in 2016, and nearly 10,000 deaths will be linked to the disease.
What the Findings of the Study Imply
The authors suggest that maintenance of a healthy weight in MGUS patients will reduce risk of myeloma progression, and that black people have to be closely followed up.
"Based on our finding that being overweight or obese is a risk factor for multiple myeloma in MGUS patients, and since extra weight is a modifiable risk factor, we hope that our results will encourage intervention strategies to prevent the progression of this condition to multiple myeloma as soon as MGUS is diagnosed," Chang said. "Also, for black people diagnosed with MGUS, close monitoring of the disease progression, in addition to maintaining a healthy weight, should be prioritized."
Future Research Plans
The researchers plan future studies to test whether weight loss and maintaining a healthy weight reduced risk of progression to myeloma in MGUS patients.
"In the future, we will look at whether healthy weight loss is inversely associated with the progression of multiple myeloma in MGUS patients or how weight change plays a role in the progression of MGUS to multiple myeloma," Chang said.