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Researchers continue to study the risk factors for the blood cancer multiple myeloma. Abraham Gonzalez Fernandez/Getty Images
  • Monoclonal gammopathy of undetermined significance (MGUS) is a blood condition that can occur before a type of cancer found in plasma cells called myeloma.
  • Some modifiable risk factors may have an association with MGUS, but more research is needed to determine their significance.
  • Experts argue people living with obesity shouldn’t be too concerned about the risk of MGUS and that other potential health complications of obesity are more urgent.

Smoking, poor sleep, and obesity may increase the risk for a blood condition that precedes a particular type of cancer, but experts say more research is needed.

Research published in the journal Blood Advances reports that some modifiable risk factors such as smoking and obesity may raise the risk of monoclonal gammopathy of undetermined significance (MGUS), a condition that can occur before a type of blood cancer known as multiple myeloma develops.

“While significant advancements have been made in therapeutics for multiple myeloma, it remains an incurable disease, often diagnosed after patients have already experienced end-organ damage,” Dr. David Lee, a co-author of the study and an internal medicine resident at Massachusetts General Hospital, said in a press release.

“It’s preceded by premalignant conditions including MGUS. Our research group is focused on investigating risk factors and etiology of MGUS to better understand who may be at increased risk for developing MGUS and its progression to multiple myeloma,” he added.

MGUS is a condition in which the blood contains higher than normal levels of a protein known as M protein.

In the majority of cases, MGUS is not problematic. The risk of a person progressing from MGUS to myeloma, a cancer of the plasma cells, is 1% per year.

In myeloma, a type of white blood cell found in the bone marrow builds up, creating tumors throughout the bones in the body.

The most significant risk factor for developing myeloma is age, with people under the age of 45 rarely being impacted by the disease.

The disease is more common in men and is twice as common in Black people than in white people.

Being overweight or having obesity is also a known risk factor for myeloma.

“There’s a well known relationship between MGUS and myeloma and obesity. This is something that has been known for some time. There’s been a link between obesity and an increased risk of individuals being found to have MGUS, smoldering myeloma or active myeloma,” Dr. Brian Durie, the chief scientific officer of the International Myeloma Foundation and a hematologist and oncologist at Cedars-Sinai Medical Center in Los Angeles who was not involved in the study, told Medical News Today.

“There’s also a correlation between obesity and a lot of other things, other kinds of cancer, other kind of things that may be going on with your immune system,” he added.

In the new study, the researchers suggest that being obese is associated with a 73% greater chance of having MGUS, when compared with individuals who don’t have obesity. However, while the researchers note a possible connection between obesity and MGUS, they note there is not enough evidence to prove causation.

Dr. Gary Schiller, a clinical investigator in multiple myeloma and hematologic malignancies at the University of California Los Angeles, argues there may be other reasons MGUS is present in a person.

“MGUS is a fairly common thing. Two to three percent of the U.S. population aged 50 and older have monoclonal gammopathy,” Schiller, who was not involved in the study, told Medical News Today. “So this is already a common entity and it’s associated with aging. So that with each 10 years of life as one goes above 50, the percentage of people who have MGUS increases. So it is also possible that that co-migrates with increasing body mass index and decreasing sleep. As I get older, I sleep less and less then wake up earlier and earlier. So if it happened that I also had MGUS then you would create an association. That association may not mean that there’s a relationship there.”

“A lot of people have looked for the last seven or 10 years on the influence of obesity and progression of MGUS and there has been some scientifically plausible explanations involving a hormone with anti-inflammatory properties that may not exist in overweight people. But right now, I think this is an association without a strong body of literature to support it,” Schiller added.

The study authors argue their research will help guide further studies into the role of modifiable risk factors and cancer risk.

“Before we can develop effective preventative health strategies to lower the risk of serious diseases like multiple myeloma, we first need to better understand the relationship between MGUS and potentially modifiable risk factors like obesity,” Lee said.

Durie argues there is not yet enough data to support the idea that making lifestyle changes in response to modifiable risk factors will make a difference to MGUS or to myeloma outcomes. But he notes some data from animal studies suggest it is an area worth investigating in the future.

“Having a modifiable risk factor is terribly important. You could have people make effort to reduce their obesity and there are data indicating that that could improve the outcomes. So this is in the big scheme of things. It’s quite important at the patient level, because it’s something that you could do about it,” he said.

Both Durie and Schiller emphasize that those living with obesity and other risk factors examined in the study should not be overly concerned about their risk for developing MGUS and, in turn, myeloma.

“Monoclonal gammopathy of undetermined significance is not a disease and not everybody with monoclonal gammopathy of undetermined significance will ever have evolution to myeloma. As a matter of fact, we estimate that the risk of progression is about 1 percent per year. The vast majority of patients with MGUS will never live to develop myeloma. They are elderly and they’ll die of an unrelated cause,” Durie said.

Schiller argues that for people living with obesity, there are other more urgent potential health risks that need to be addressed.

“I’m not sure that MGUS is a disease entity in search of prevention,” he said. “I think there’s so many other things that obesity is associated with that are disease states that are truly immediately life threatening, like hypertension, and diabetes, hyperlipidemia and consequent stroke and heart attack. I think that those abnormalities, those diseases really present a much more urgent need to prevent than MGUS.”