• Posted October 2, 2023

Diabetes Could Speed Progression of Blood Cancer Myeloma

Diabetes may accelerate the growth of a blood cancer known as multiple myeloma, affecting overall survival, according to a new study.

The research, published Sept. 29 in the journal Blood Advances, also underscores differences in survival outcomes for Black patients versus white patients with both conditions. In this study group, diabetes affected survival rates in white patients, but not in Black patients.

"We knew from prior studies that patients with multiple myeloma and diabetes have lower survival rates, but what we did not know is how these outcomes differ between races,"said study author Dr. Urvi Shah, multiple myeloma specialist at Memorial Sloan Kettering Cancer Center in New York City.

"Diabetes is much more common in Black individuals versus white individuals, and we wanted to understand whether this difference may play a role in health outcomes among patients with both conditions," she said in a journal news release.

Multiple myeloma is cancer of plasma cells in the bone marrow. It is the second-most common blood cancer in the United States. Among Black adults, it is the most common.

Diabetes affects about 13% of the U.S. population, and the rate is on the rise, according to the U.S. Centers for Disease Control and Prevention.

For the study, researchers examined electronic health records of more than 5,300 patients with multiple myeloma who were treated at two academic medical centers.

Fifteen percent had a diabetes diagnosis, including 12% of white patients and 25% of Black patients.

Patients with myeloma who also had diabetes had poorer survival rates than those without diabetes.

When researchers broke this down by race, white patients with myeloma and diabetes had lower survival rates than those without diabetes. They didn't see this in Black patients, however.

"What we did not expect to see here was that diabetes was actually associated with worse survival outcomes among white individuals with myeloma, but not Black individuals,"Shah said.

Generally, a person's risk for diabetes increases with age, Shah said. Overall survival declines with age.

However, in this study, diabetes was 50% more prevalent among Black patients between 45 and 60 years old than in white patients over 60.

Researchers said younger patients may tolerate multiple myeloma treatments better than older individuals, which could explain some of the racial differences they observed in survival outcomes.

Researchers also investigated tumor growth in genetically engineered mouse models. They found that multiple myeloma tumors grew faster in non-obese diabetic mice than in non-diabetic controls.

An insulin-related signal was overactivated in the diabetic mice, researchers found. Higher insulin levels associated with diabetes may speed up cancer growth.

"In my own practice, I work with many patients with both multiple myeloma and diabetes. And usually treating multiple myeloma involves many rounds of chemotherapy,"Shah said. "But this study suggests that we may also improve patient outcomes further by treating diabetes at the same time."

In the future, Shah hopes to identify therapies that stop development of multiple myeloma as well as the overactive insulin signaling pathway in patients with multiple myeloma and diabetes.

She is also investigating whether making changes in one's microbiome and diet may improve cancer outcomes.

More information

The American Cancer Society has more on multiple myeloma.

SOURCE: Blood Advances, news release, Sept. 29, 2023