What Is the Link Between Sleep Apnea and Cancer?

Several sleep studies have found a connection between sleep apnea and an increased risk for cancer development and cancer death. Researchers are beginning to realize that certain aspects of sleep apnea might encourage the growth of tumors. While more research is still needed, they theorize that a likely culprit could be low oxygen from repeated breathing obstruction.

What Is Sleep Apnea?

Sleep apnea is a sleep disorder that causes dangerous pauses in breathing during sleep. According to the American Sleep Apnea Association, up to 22 million Americans have sleep apnea, although many of these cases are undiagnosed. 

This condition is practically concerning for sleep doctors because it causes the body to become deprived of oxygen at night and may coincide with other life-threatening diseases, including diabetes, cardiovascular disease, and cancer.

The most common symptoms of sleep apnea are snoring and restless sleep. Additional symptoms include:

• Morning headaches
• Lack of energy during the day
• Daytime fatigue
• A sore throat or dry mouth upon waking
• Mood problems, including irritability
• Insomnia

Treatment includes making lifestyle modifications, including weight loss, quitting smoking, and limiting alcohol consumption. When lifestyle changes don’t help, therapies such as a CPAP (continuous positive airway pressure) machine are considered. Nasal and sinus surgeries may also help in severe cases.

Cancer Connection

Several studies have found an increased risk of cancer development and cancer death in people with sleep apnea. The theory backed by many researchers is that blockage of someone's airway may promote a process called neovascularization, which is the growth of new blood vessels. This process may end up encouraging tumor growth.

In 2013, Spanish researchers reported that people with severe sleep apnea had a 65 percent increased risk for cancer. They suggested the risk is associated with increased hypoxia, a condition where the body is deprived of oxygen. 

Another study from the University of Wisconsin found people with sleep-disordered breathing are five times more likely to die from cancer than people without sleep apnea. Researchers from the American study admit the study is limited in that there are no studies to compare it with that look at cancer survival in people with sleep apnea.

One recent study reported in the Journal of Sleep Medicine shows moderate and severe cases of sleep apnea are associated with increased cancer risk. That study also showed an increased risk for all “all-cause mortality” and cancer mortality due to cancer. The 20-year study showed that people with moderate to severe cases of sleep apnea are two and a half times more likely to develop cancer and three times more likely to die from cancer. The authors noted these findings confirmed previous research conducted by American and Spanish researchers.  

Animal studies have also confirmed previous findings. One 2014 study reported in the journal Cancer Research linked sleep apnea with aggressive cancer growth in mouse models. Mice with tumors were placed in low oxygen environments that mimic the effects of sleep apnea and tumor growth in the mice progressed rapidly.

Link to Specific Cancers

Research also links specific cancers to sleep apnea. For example, one older study finds that 80 percent of head and neck cancer patients also have sleep apnea.

One 2016 study finds a connection between aggressive melanomas and sleep apnea. The researchers of this study examined 412 patients with malignant melanoma. What the researchers found was that the most aggressive cases were in people who had the most severe sleep apnea symptoms. 

One Taiwanese study finds breast cancer rates are higher for women with sleep apnea. The risk seems to be highest in women under 30, but the study wasn’t big enough to confirm that age plays a part. 

Another recent study reported in the journal Sleep finds that sleep apnea increases the risk for certain types of cancer. These researchers did not find any increased risk for metastatic cancer (cancer that starts in one part of the body, i.e. breast, and spreads to another part, i.e. lungs) or cancer mortality.

Preventing Sleep Apnea

Both sleep apnea and cancer are widespread conditions. They are also treatable and preventable. Prevention usually relies on making healthy lifestyle choices, including:

• Quitting smoking
• Not consuming alcohol in excess
• Weight management
• Treatment of all current medical conditions
• Improving sleep quality

A Word From Verywell

It's important to take sleep apnea and sleep problems seriously, especially because of sleep apnea’s connection to a number of diseases. The number of people with sleep apnea is increasing, as is the number of people who are overweight. It is therefore important to look for the signs and symptoms of sleep apnea, including loud snoring, daytime fatigue, and interrupted breathing during sleep. Anyone who suspects they or someone they love could have sleep apnea should consider having themselves—or loved one—checked out.