Obstructive sleep apnea (OSA) is a common and potentially life-threatening medical disorder affecting about one in four Americans. OSA is characterized by snoring and gasping caused by a partial or complete collapse of the airway during sleep. The result is reduced oxygen to all body organs including our brain. In addition to symptoms such as daytime sleepiness and snoring, OSA can cause memory problems, reduced sex drive, morning headaches, depression, moodiness, insomnia and poor concentration.
For years, research has shown that people with OSA have an increased risk of diabetes, obesity, car accidents, high blood pressure, stroke, heart attack and sudden death. Up until recently, we lacked information on the link between OSA and cancer. However, this subject is getting serious attention due to two new studies.
Researchers in Spain followed 5,600 patients for seven years and found that patients with severe OSA had a 65 percent greater chance of developing cancer. The risk of dying from cancer for young male patients with untreated OSA was even greater.
A 22-year study of mortality data on 1,522 Wisconsin government employees with severe OSA found the death rate due to cancer to be five times greater than those who had no nighttime breathing problems.
Both studies were presented by the American Thoracic Society at the 2012 International Conference in San Francisco. Researchers ruled out any possibility that usual factors for cancer like age, smoking, alcohol use, physical activity and weight could have played a role in the research findings.
Additionally, when mice with cancerous tumors were placed in low-oxygen environments similar to that of OSA conditions, their cancer progressed more rapidly. The lack of oxygen stimulates the growth of blood vessels that nourish tumors and cause them to grow (a process known as angiogenesis). Dr. F Javier Nieto, chairman of population health studies at the University of Wisconsin stated, "The consistency of evidence from animal experiments, and this new epidemiologic evidence in humans is highly compelling."
Neither study confirmed the effect of treatment for OSA with regards to reducing the risk of cancer, and more research is needed to confirm these findings. Until we understand more about the link between cancer and obstructive sleep apnea, it makes sense to get screened, diagnosed and treated for OSA if your family has a history of obesity, cardiovascular disease and/or cancer!