Sleep Apnea and Cancer Risk

Database Provides Statistical Power

In one study published in the European Respiratory Journal, researchers drew from the European database ESADA, which included about 20,000 adult patients with sleep apnea. About 2% of these patients had a cancer diagnosis.

The study found first that cancer risk was linked to age, but beyond that, it was also linked to breathing stoppages during sleep. That’s after correcting for various risk factors such as:

• Gender
• Body mass index (BMI)
• Smoking
• Alcohol consumption

The study showed that the risk was higher for women with intermittent sleep hypoxia. Severe sleep apnea may have as much as tripled the cancer risk for women. For men, cancer risk was also elevated, but the statistical significance of this increase was lower.

Recent Review Confirms Association

In 2022, researchers conducted an updated meta-analysis of the data linking sleep apnea and cancer risk. This article included 22 studies covering a total of 32 million patients! That’s a lot of statistical power.

In this review, people with sleep apnea were 53% more likely to develop cancer than people without the condition.

Not a Causal Link

Researchers caution that this study doesn’t actually say that sleep apnea causes cancer in women. However, it strongly hints at mechanisms that could contribute to elevated cancer risk. Researchers proposed that this link could be related to female sex hormones and stress activation, which could either trigger the development of sleep apnea or weaken the body’s ability to fight cancer during its early stages.

They also proposed that more work should be done on specific cancers, such as breast cancer, womb cancer, or cervical cancer, that affect women.

A Detroit sleep dentist can help you get a sleep test so that you will understand your cancer risk and can make more informed decisions.

Sleep Apnea and Breast Cancer Risk

There have been a few considerations of the relationship between sleep and breast cancer risk. For example, some have looked at the increased risk of breast cancer related to shift work, but not much has been done for sleep apnea.

There are a few quality studies, though, that compare breast cancer rates among women with sleep apnea to those among a control group. This Taiwanese study compared 846 women diagnosed with sleep apnea with 4230 age-matched controls. The women were followed for five years, and their cancer rates were compared.

Twelve (12) women in the sleep apnea group developed breast cancer in the follow-up period, compared to 32 in the control group. After adjusting for known cancer risks, researchers found that this was essentially a doubling of breast cancer risk.

More recently, a large meta-analysis looked at six studies that combined the records of more than 5 million patients. This study concluded that women had a 36% higher risk of breast cancer. Unlike most of these types of studies, this study did provide some evidence that the link might be causal: sleep apnea might cause breast cancer.

Women Should Be Screened for Sleep Apnea

Sleep apnea is more common among men than women at younger ages, but once women pass menopause, sleep apnea risk becomes about equal. With serious health risks like heart disease, diabetes, and dementia being associated with sleep apnea as well as breast cancer, women should be aware of their risk and talk to their doctor or a sleep dentist if they experience symptoms of sleep apnea such as:

• Daytime sleepiness
• Chronic fatigue
• Depression
• Loss of drive
• Inability to focus
• Memory problems

Snoring should also be considered a warning sign for sleep apnea. If your cosleeper or others in the house report snoring, you should take it seriously and bring it up with a doctor or contact a Detroit sleep dentist.

Short Sleep Linked to Worsened Breast Cancer Survival

It’s another good reason to get snoring treated and make sure you’re getting enough sleep: it could improve your odds of surviving cancer. An analysis of a large pool of data shows that snoring and short sleep are correlated with lower cancer survival rates, especially breast cancer.

This insight comes after researchers analyzed data from the Women’s Health Initiative (WHI). Begun in 1991, the WHI includes a population of over 120,000 postmenopausal women. Researchers collected a large amount of data from these women when they joined the study, including how long they slept on average every night and whether they snored. Then women in the study were observed for over ten years.

Over the course of the study, more than 21,000 women developed cancer of some type. Researchers then analyzed the data from these women to determine the potential link between snoring, sleep, and cancer survival. They discovered that women who reported short sleep duration (≤ 6 hours) and frequent snoring (5 or more nights a week) had significantly poorer survival rates, being 1.32 times more likely to die following a cancer diagnosis.

Breast cancer survival rates were independently linked with short sleep (1.46 times less likely to survive) and snoring (1.34 times less likely to survive), and women who had both were about twice as likely to die of breast cancer than those who slept 7-8 hours and didn’t report snoring.

Sleep Apnea Could Make Cancer More Aggressive

The breast cancer study wasn’t designed to determine whether a causal link existed between the two conditions, but there are some intriguing potential ways that there could be a causal link between poor sleep and poor cancer survival. Perhaps the strongest potential link is inflammatory hormones.

Inflammatory hormones have been shown to increase a person’s cancer risk. Our body also can’t regulate inflammatory proteins as well when we get poor sleep. This includes both short sleep and sleep disrupted by snoring or sleep apnea. An excess of inflammatory proteins could contribute to cancer growth, making a person’s odds of success lower.

However, a better answer might come from a study looking specifically at mechanisms that link sleep apnea to cancer. Researchers at the University of Chicago and the University of Barcelona have shown that sleep apnea can change exosomes, and vital signals between cells, making cancer more aggressive.

Given this, it makes it critical that women in Detroit should consider a sleep test to see whether they have sleep-breathing disorders like sleep apnea.

Understanding Exosomes

Exosomes are a communication method that our cells use to carry vital information between them. An exosome is a vesicle–a packet of material enclosed in a lipid layer (similar to the cell membrane)–that emerges from the cell into the fluid of the body. It can be various molecules, but it can also be an actual cell organ.

We know that in addition to carrying information between healthy cells, exosomes can carry information between cancer cells and may be vital to the signaling process that turns a tumor malignant. They also help cancerous tumors grow their blood supply to support growth. And they can help protect cancer cells from attack by the immune system.

With all these key roles for exosomes, influencing exosomes would be a powerful method for controlling cancer–or worsening it.

Exosomes, Lung Tumors, and Sleep Apnea

Researchers wanted to see if lung tumors responded to sleep apnea. To test this, they took mice who had developed lung tumors. Half of the mice were kept in a normal atmosphere. The other half were exposed to intermittent hypoxia (oxygen shortage) to simulate the effects of sleep apnea.

The mice that were exposed to hypoxia saw more growth in their lung tumors. Their bodies also released more exosomes that contained RNA (genetic messenger molecules) that stimulated cancer.

Sleep Apnea Treatment: Better Health and Longer Life

This research reminds us how important it is to treat sleep apnea. The myriad health effects of this condition can combine to dramatically increase your risk of death at a young age. For example, one 2014 study showed that sleep apnea is linked to a fourfold increase in the risk of all-cause mortality. This includes a tripling of the death risk from cancer. Other studies show as much as a sixfold increase in mortality risk. Detroit sleep dentist Dr. Haddad can help you get sleep apnea treatment, which could be as life-saving as it is life-changing.

Understanding the mechanism that links sleep apnea to cancer growth shows us another way that sleep apnea treatment contributes to better health and longer life.

If you are suffering from sleep apnea, don’t wait until you get a wake-up call in the form of a cancer diagnosis. Instead, get it treated today to help reduce your serious health risks.

If you would like to learn more about these snoring solutions in the Detroit area, please call (248) 480-0085 for an appointment with a sleep dentist at the Michigan Center for TMJ & Sleep Wellness in Rochester Hills near the Sanctuary Lake Golf Course.