Researchers at the University of Iowa have discovered a link between sleep apnea and multiple myeloma, a deadly blood cancer, that could lead to earlier and more effective treatment of the disease.
Mahmoud Ali, the study’s lead author and a postdoctoral researcher at the UI, says the findings provide a better understanding of how sleep apnea may drive multiple myeloma.
“Multiple myeloma is a serious type of cancer, and it’s incurable right now,” says Ali. “We’re trying to look at what could be a modifiable factor so we can prevent or decrease the risk of people developing the cancer.”
Multiple myeloma is a cancer in plasma cells, which are an important part of the immune system. As the cancer progresses, it collects in bone marrow and destroys the solid parts of bones. It is expected to be the 10th deadliest cancer among Iowa women in 2019, according to this year’s Cancer in Iowa report published by the UI College of Public Health.
Melissa Bates, an assistant professor of health and human physiology and principal investigator on the study, says previous research has shown a link between obesity and multiple myeloma. Studies also have suggested that sleep apnea—a condition common in people who are obese—increases the risk of dying from cancer. But while previous research looked at solid cancers such as lung, breast, and colon cancer and sleep apnea, this study is the first to explore the link between sleep apnea and multiple myeloma.
Specifically, the study examined how gene mutations and sleep apnea cooperate to drive the cancer by using specially bred laboratory mice that are resistant to multiple myeloma. Researchers injected the mice with malignant mouse multiple myeloma cells. Those mice were then put into an environment simulating the effects of sleep apnea.
About 70 percent of the myeloma-resistant mice developed the disease after being exposed to the sleep apnea conditions. Furthermore, the cancer cells were primarily found in the bone marrow of the mice exposed to sleep apnea. In humans, multiple myeloma weakens bones, and people with the disease are affected by bone pain and fractures.
Researchers say the findings suggest sleep apnea may be a risk factor that doctors should ask patients about.
“In the near term, if someone has myeloma or a pre-myeloma condition, we really should be asking them about sleep apnea and sleep-disordered breathing,” says Michael Tomasson, professor of internal medicine in the Division of Hematology, Oncology and Blood and Marrow Transplantation at the UI and a researcher on the study. “Treating sleep apnea might be something we could do more to reduce the risk of getting myeloma or to increase the effectiveness of treating the disease.”
Bates says the findings also give cancer patients a way to play an active role in their treatment by addressing their sleep apnea.
“It’s potentially a very potent driver of cancer aggression,” she says. “It’s so simple. It had such a profound impact, but it’s potentially so treatable.”
Researchers are now working with multiple myeloma patients at University of Iowa Hospitals & Clinics to track sleep apnea and see how addressing the sleep disorder influences their response to chemotherapy, symptoms from the disease, and survival rate.
“It’s really exciting to be able to contribute in that way,” Bates says. “We know the Holden Comprehensive Cancer Center is the best place in Iowa to get treatment for cancer. To see our study is potentially giving new options to help people is really rewarding.”
The study, “Chronic Intermittent Hypoxia Enhances Disease Progression in Myeloma-resistant Mice,” was published in the American Journal of Physiology, Integrative and Comparative Physiology in March. The study was funded by a grant from the American Cancer Society administered by Holden Comprehensive Cancer Center.
Co-authors of the study are Chakrapani Tripathi, Hongwei Xu, and Fenghuang Zhan from the UI Department of Internal Medicine, Hematology and Oncology Division; Sandeep Kowkuntla and Derick J. Delloro from the UI Department of Health and Human Physiology; Siegfried Janz from the UI Department of Pathology; Deep Hathi from the Washington University Department of Radiology; and Csaba Galambos from the University of Colorado School of Medicine and Children’s Hospital Department of Pathology and Laboratory Science.