Women with Sleep Apnea May Have Higher Risks for Cancer

Emerging research shows that women who have severe sleep apnea could be at a higher risk of developing cancer. Though these researchers did not identify the mechanism by which these two may be intertwined, they found a strong correlation between cancer risk and sleep apnea in women. This work was published in the European Respiratory Journal.

“It’s reasonable to assume that sleep apnea is a risk factor for cancer, or that both conditions have common risk factors, such as overweight,” explained study author Ludger Grote, Adjunct Professor and chief physician in sleep medicine. “On the other hand, it is less likely that cancer leads to sleep apnea.”

This work was based on an analysis of registry data from the European Sleep Apnea Database (ESADA). The researchers extracted data regarding roughly 20,000 adult patients with obstructive sleep apnea from this system to evaluate the potential correlation between the condition and cancer risk. Of this entire patient population, about 2% had a cancer diagnosis.

Unsurprisingly, data from patients of older age showed that they were at an elevated risk for cancer. Once the team adjusted for age, gender, BMI, and cigarette and alcohol use, they identified a potential link between intermittent hypoxia and higher cancer incidence. Hypoxia, the state of having inadequate oxygen, is characteristic of sleep apnea. This effect was much more pronounced in women than it was in men.

“Our results indicate a cancer risk that’s elevated two- to three-fold among women with pronounced sleep apnea,” explained Grote. “It’s impossible to say for sure what causes underlie the association between sleep apnea and cancer, but the indication means we need to study it in more depth.”Grote is the Adjunct Professor of Pulmonary Medicine at Sahlgrenska Academy, University of Gothenburg, specializing in sleep medicine.

“The condition of sleep apnea is well known to the general public and associated with snoring, daytime fatigue, and elevated risk of cardiovascular disease, especially in men. Our research paves the way for a new view — that sleep apnea may possibly be connected with increased cancer risk, especially in women,” he continued.

Previous literature confirms these findings that those with sleep apnea are potentially at an elevated risk for developing cancer. What is unique to Grote and colleagues’ findings is that gender may play a significant role in this risk as well.

“Above all, the focus has been on the connection with one form of cancer: malignant melanoma. Cancer of the breast or womb may now become a new area. There may be a combined effect of female sex hormones and stress activation, induced by nocturnal hypoxia in sleep apnea, that can trigger cancer development or a weakening of the body’s immune system,” Grote concluded.

First author Athanasia Pataka who is associated with the George Papanikolaou Hospital and Aristotle University of Thessaloniki in Greece, writes that the intermittent hypoxia and sleep disruptions brought about by sleep apnea may play a role in cancer angiogenesis. Other suspected mechanisms include “sympathetic outflow, or modulation of immune function and tumour microenvironment.”