Glioblastoma patients suffering from undiagnosed sleep apnea have a significantly higher risk of death than other patients, according to a study led by two medical students at Brown.

Justin Bessette and Jonathan Arditi reviewed the records of nearly 1,000 patients admitted to Rhode Island Hospital between 2005 and 2022. While age and the number of medical conditions heavily influence survival rates, the study, published in the British Journal of Cancer Reports, revealed that the risk of death is at least three times higher for those suffering from obesity and atrial fibrillation.

The student researchers hypothesized that underlying, untreated sleep apnea—which is closely associated with both obesity and atrial fibrillation—is the true culprit behind these worsened outcomes. Sleep apnea is already associated with a host of health problems like diabetes, stroke, and respiratory failure.

“Quite a lot of research has been done on the tumors themselves, but researchers have not focused on the environment outside of the tumor, particularly co-morbidities that are lurking in these patients,” says Eric T. Wong, MD, the director of medical neuro-oncology at the Brown University Health Cancer Institute.

Bessette says they initially focused on analyzing the connection between patients’ history of cancer and glioblastoma outcomes, but they found a complex web of medical comorbidities among them.

“There were all of these patients who had so many other things going on other than cancer, so I got the idea that maybe there are other conditions affecting the survival rates in them,” he says.

Bessette says they examined everything from hypertension and heart conditions to psychiatric disorders. Arditi entered the picture when it came time to do a deeper statistical analysis on the correlation between some of the specific factors and survival rates.

“I wanted to look at pairs of comorbidities and examine how survival rates change versus having both or only one,” Arditi says. “That’s how we began to discover the relationship between obesity and atrial fibrillation among patients, and the implication for sleep apnea.”

Wong, a professor of medicine, of radiation oncology, of neurology, and of neurosurgery at Brown, says their data also demonstrated how metabolic diseases, like hypertension and type 2 diabetes, are deeply intertwined with survival rates. Patients suffering from obstructive sleep apnea may have these two underlying conditions as well.

The researchers hope to validate their findings further with a new dataset at another institution, and perhaps even construct a clinical trial to test the hypothesis that correcting obstructive sleep apnea may prolong survival.