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Cancer (along with cardiovascular disease) is a leading cause of death in the United States, and sadly affects a lot of people. It’s not unreasonable to assume that cancer can create sleep problems, but the amount of factors put into play by this condition is often overlooked. Not only can you get awakened by the pain associated with cancer, but the treatment options can get in the way of your rest, too. Prescription medication often has unwanted and unpleasant side-effects that can ruin your already damaged sleeping pattern, and chemotherapy has its share of downsides.
On top of that, getting insufficient rest is a severe risk for your immune system. As a result, there is evidence that supports the fact that a lack of sleep can itself lead or contribute to cancer. A vicious cycle can form for cancer patients, where cancer (and its treatment) causes poor sleep, weakening their immune system, which opens them up to various other illnesses and health risks, and exacerbates the symptoms of cancer and the discomfort, making them sleep even worse. In order to get some relief in this whole situation, it’s important to understand how cancer is connected to various sleep problems, and what to do if you’re struggling to fall asleep as a cancer patient.
Can a Lack of Sleep Cause Cancer?
We don’t have enough evidence that points towards sleeping as a contributing factor or a direct cause of cancer, thankfully. There is no reason as of yet to avoid getting a good night’s sleep (usually around 7-8 hours for adults) because sleep deprivation can be very harmful. It can be a disorder in itself and is one of the most common and easily noticed symptoms of other conditions. It’s hard to observe sleep deprivation in a vacuum as it has many potential causes, including ones that spontaneously occur during the day at no fault of the person in question. We will look at three sleeping disorders and examine how they contribute to the risk of cancer.
Chronic Sleep Deprivation and its Connection to Cancer
Chronic sleep deprivation is not an uncommon condition to face, and it has at least a handful of nasty outcomes for many activities and aspects of life. Here’s a brief list of sleep deprivation and fatigue consequences and risks, to paint a clearer picture:
- Your immune system gets weakened, leaving you vulnerable to many separate diseases and other conditions
- Unwanted weight loss or weight gain, depending on the individual. Not everyone is affected the same way by sleep deprivation
- Irritability and increased aggression are common among the sleep-deprived. It encourages the person to take more risks, which can cause workplace accidents. Fatigued people are also more susceptible to depression and similar issues
- Slower reaction times and worse hand-eye coordination are especially impactful for drivers and occupations where you need precision and sharp reactions.
- Worse memory and weakened cognitive power, which causes the person to have trouble processing new information, have worse judgment, etc.
Many things can contribute to or cause this condition. A common example is a hectic and busy work schedule, especially if you have to swap shifts – this situation can seriously ruin your sleeping pattern and reduce the time you spend in deep or REM sleep. Other causes can include depression, insomnia or similar conditions since those all hinder your ability to get proper rest. Finally, environmental issues like a noisy room can wake you up or increase your sleep onset latency. These causes can be hard to avoid or work around, which makes sleep deprivation a common problem for most people, even if only in short bursts.
Unfortunately, chronic sleep deprivation has been connected to cancer in a worrying number of studies. For example, post-menopausal women have a higher chance of getting a more aggressive version of breast cancer if they sleep less than they should. The chances of a man encountering prostate cancer double if they have chronic sleep deprivation and both genders have a significantly increased risk of colorectal cancer if they get less than six hours of rest per night on average.
Shift Work Sleep Disorder and its Connection to Cancer
Shift workers are in a very tough spot when it comes to their sleeping patterns and overall health. They often cannot hold a steady sleep pattern due to their ever-changing work shifts, which kicks their circadian clock off-balance and affects many processes in their body for the worse. It’s important to remember that the circadian rhythm controls more than just when you fall asleep or wake up – hormone secretion, body temperature, and similar systems are also affected when your circadian rhythm is disrupted. When the processes in your body are disrupted, it invites disease like few other things. Shift work sleep disorder (SWSD) is just one of several circadian rhythm disorders, but it has the strongest link to prostate, colon, ovary and breast cancer.
Breast cancer appears 30% more often in women who work night shifts, even if they don’t spend every workday handling the late shift. No matter how often it happens, the increased cancer risk is present – even for women who have grown “accustomed” to their new sleeping schedule after years of nothing but night shift work. It is suspected that this connection to cancer stems from what circadian rhythm disruption does to a person’s melatonin and cortisol production. The master clock regulates melatonin production, and that production is crippled for shift workers, leading to a reduced amount of melatonin overall – and this deficit directly contributes to an increased risk of cancer, For women, a lack of melatonin increases estrogen production, which can invite cancer if it’s present in excessive amounts. Similarly, cortisol production is delayed or disrupted, which means the level of cortisol in your body is delayed until the afternoon if you have to cover late shifts. While there hasn’t been enough research to make a full conclusion, this issue with cortisol is suspected of being a contributing factor to cancer.
Sleep Apnea and its Connection to Cancer
Sleep apnea is a sleeping disorder characterized by a temporary reduction or loss of breath while sleeping. As a result of this loss of breath, the sleeper may experience choking, loud snoring or gasping, which is almost guaranteed to wake them up multiple times each night, forcing them to suffer from fragmented sleep and all the consequences of the resulting fatigue. Most people will encounter two types of this disorder – central sleep apnea (CSA) and obstructive sleep apnea (OSA). OSA is caused by a physical blockage in the airways. While the person is sleeping, their throat muscles relax enough to let the tongue block the airway. CSA is characterized by the brain’s inability to properly regulate breathing muscles by sending electrical signals. Both types of sleep apnea are dealt with using PAP (positive air pressure) treatment, despite not having a real cure.
Sleep apnea has been linked to various health problems for a long time, such as cardiovascular disease, diabetes or obesity. However, recent material also points towards cancer as a very likely potential result of sleep apnea. A whopping 80 percent of head or neck cancer patients have sleep apnea (though it’s not always severe), and the overall risk of death from cancer is 65 percent higher for those with severe sleep apnea. These results were replicated using animals such as rats – cancer growth is accelerated in rats who have breathing problems. The main theory researchers offer is that oxygen deprivation leads to an increased amount of blood vessels created by the body in order to compensate, which lets cancer grow and spread faster.
How Cancer Affects Your Sleep?
More than 50 percent of adults currently undergoing cancer treatment encounter some sort of problem sleeping. Not only cancer itself causes massive discomfort and pain, but the treatment procedures are also not exactly sleep-friendly. Both medication use and chemotherapy cause enough problems to disrupt your sleeping pattern (such as night sweats or hot flashes) and force you to go through fatigue. Additionally, you become more vulnerable to depression and anxiety – incredibly common causes of insomnia and similar sleep disorders. We will examine some of the most common sleeping disorders caused by and associated with cancer – insomnia and restless leg syndrome.
Insomnia and Cancer
Insomnia is possibly the most commonly known sleep disorder, and it appears here as a very likely outcome of cancer treatment – affecting around 30-50 percent of all cancer patients. Both chemotherapy and “regular” medication contribute to insomnia. Chemotherapy medicine is well known to cause considerable amounts of fatigue, and it’s very easy to doze off during the day as a result. However, these daytime naps create sleeping problems when it’s time for a full night’s rest, which manifests as full-blown insomnia.
Additionally, dealing with cancer inevitably causes a lot of anxiety, stress, and general emotional instability. These issues only reduce your chances of getting a restorative night of uninterrupted sleep. Be sure to seek out support from your friends and family, as this is one of the most difficult periods of life you could ever face.
The main medication you get to supplement the chemotherapy plan are steroids, which are known to cause disrupted or fragmented sleep and increase sleep onset latency (the time it takes you to fall asleep). In order for your body to recover properly during the night, you cannot afford sleep interruptions. Every time you wake up in the middle of the night, you lose out on a portion of deep and REM sleep that you need for physical and mental repairs. As a result of this, you wake up tired and groggy, and the symptoms of cancer slowly get amplified. Another type of medication used to relieve the side-effects of chemotherapy is anti-nausea pills. The problem with this medication is that it increases drowsiness – especially during the day. It is another source of “temptation” that can lead to daytime naps and overall poor sleep quality.
Restless Legs Syndrome (RLS) and Cancer
Studies show that restless legs syndrome affects a lot of cancer patients who are undergoing chemotherapy. Tools like the Pittsburgh Sleep Quality Index (PSQI) and the Hospital Anxiety and Depression Scale were used on third-stage chemotherapy patients, and the results are very clear. 20% of patients screened positive for restless legs syndrome, and over half of all patients reported sleep disturbances. According to the tests conducted by researchers conducting this study, both RLS and sleep disturbances, in general, are directly or indirectly linked to the level of discomfort and stress caused by chemotherapy and supplemental medication. Experts suggest that patients suffering from RLS should have their treatment plan altered to work around this condition, as the amount of lost sleep only amplifies their symptoms overall.
Additionally, it has been discovered that people who have cancer are around twice as likely to encounter restless leg syndrome – especially men (older than 50 years) dealing with prostate cancer and women dealing with breast cancer.
Additional Therapy Options
If you’re struggling to fall asleep as a result of cancer treatment, some forms of therapy can at least alleviate that problem. While it eats up more of your spare time, additional therapy can improve your quality of life and strengthen your immune system through improved sleep quality and quantity. These options include:
- Light therapy, a treatment method that helps fix a disrupted circadian rhythm without the use of medication, by exposing the patient to light boxes or special lamps that stimulate the biological clock’s light receptors. Depending on which “direction” your circadian rhythm was pushed, you will either engage in light therapy in the morning or afternoon.
- Sleep restriction therapy (SRT) is a method used to fight insomnia by reducing the amount of time the patient spends in bed without sleeping. SRT essentially forces enough sleepiness on the patient that their sleep onset latency is drastically improved when the time comes to head to bed. Any activities in bed that aren’t sleeping or sex are eliminated from their routine. It may be hard to avoid daytime naps, but it pays off in the long run.
- Cognitive behavioral therapy (CBT) trains the patient’s mind to recontextualize sleep and associate comfortable and positive feelings with their bed and sleeping environment to combat insomnia. It often involves relaxation exercises and some form of stimulus control, which tends to resemble sleep restriction therapy in its approach and goals.
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Michael is a professional writer based in Boston and someone who has always been fascinated with the mysteries of sleep. When he’s not reading about new sleep studies and working on our news section, you can find him playing video games or visiting local comic book stores.