I will never forget when my Dad was diagnosed with cancer more than ten years ago. For the first week after we received the news that he had Chronic Lymphocytic Leukemia, hardly anyone in the family slept. While most of us did eventually catch up on rest and got back into our normal patterns, insomnia and fatigue became a daily struggle that my Father faced for many years.
Sleep disturbances and fatigue are all too common in those battling this horrible disease. According to the National Cancer Institute, between ⅓ to ½ of all those newly diagnosed experience sleep difficulties at some point.
If you are looking for answers to these questions, you are not alone.
We’ve unpacked some of the research on the connection between sleep and cancer, including risk factors, common sleep disorders, and some tips on how to improve sleep if you are already experiencing a lack of shut-eye.
Keep reading for the full scoop on this important issue.
More and more research is being done on the link between sleep and cancer. Many lifestyle factors like smoking, excessive alcohol and lack of exercise have been known to increase the risk of certain types of cancer, but some preliminary research has shown that lack of sleep may play a role, too.
We also know that chronic sleep deprivation is associated with obesity, diabetes, and many other potentially serious health conditions that are themselves risk factors for cancer.
Chronic sleep deprivation can wreak havoc on the body and brain. Missing out on the recommended 7-8 hours a night can lead to trouble with memory, thought processing, poor judgment, weight irregularities, insulin resistance, lowered immunity, and an increased risk for mental health issues including depression and anxiety.
Typically, the body cycles through light, deep, and REM sleep (rapid eye movement). Each stage is important. Deep sleep is important for muscle and tissue repair, and the REM cycle is when the mind processes memories, dreams, and emotions. Missing out on these stages can lead to physical, emotional, and cognitive effects because the body has not had sufficient time to repair.
Cancer patients are at a higher risk of developing insomnia and other related conditions stemming from both the physical and psychological aspects of the disorder. Hospitalization, side effects of treatment, pain, and fears around recent diagnosis are all factors that can contribute to trouble sleeping.  Even after going into remission, many cancer survivors report ongoing battles with insomnia as long as a decade later.
Unfortunately, prolonged use of these sedatives may also contribute to the disease itself. A recent meta-analysis of several observational studies found that the use of hypnotics may increase the risk of cancer over time.
Using sleeping medications may also interfere with restorative REM rest leading to confusion, irritability, and lethargy. Withdrawal side effects can be especially difficult for most people, leading to shakiness, anxiety, seizures, and a potentially harmful condition known as “REM rebound.”
Risk factors for insomnia and similar disorders in cancer patients include the following:
There is still so much we don’t know about how sleep disturbances and disorders are linked to cancer, but more and more evidence is pointing to a connection. While research is still ongoing, several studies have investigated how a lack of sleep may increase cancer risk.
Sleep apnea is a pattern of disrupted breathing where a person will periodically hold their breath for seconds at a time while asleep. A twenty-year study published by the American Academy of Sleep Medicine involving 397 adults found that those with moderate to severe obstructive apnea were 2.5 times more likely to develop cancer.
Another study in Wisconsin using 22 years of data to examine 1,522 patients found that those with severe apnea had a 4.8 times higher mortality rate. Other studies have shown mixed results, and one Canadian study found no link between sleep apnea and cancer.
There is consistent evidence that shows a higher incidence of cancer in obesity, and sleep apnea is also correlated with obesity. Additional research is needed to determine if the link between this disorder and cancer is related to obesity or whether decreased oxygen to the brain during apneic episodes may somehow increase cancer risk.
About 20% of Americans have jobs that involve shift work. Many people love working night shift, either because it is more relaxed and quiet, or for the additional pay some companies offer for working these erratic hours. Unfortunately, many people are unaware that shift work may cost them more than it is worth – increasing their risk of cancer.
27 scientists from 16 countries recently met in France to discuss their latest findings on the carcinogenicity of night shift work and reported the following:
“There is robust evidence in both humans and experimental animals that alteration in the light–dark schedule results in changes in serum melatonin and in the expression of core circadian genes. With respect to key characteristics of carcinogens, the Working Group found that there is strong mechanistic evidence in experimental systems, based on effects consistent with immunosuppression, chronic inflammation, and cell proliferation.”
In summary, they found that in certain populations, working the night shift is “probably “carcinogenic to humans”, based on limited evidence of cancer in humans, sufficient evidence of cancer in experimental animals, and strong mechanistic evidence in experimental animals.”
Shift work often leads to a disruption of the normal rest-wake patterns known as the circadian rhythm. The human body has an internal biological clock that responds to periods of light and darkness, releasing hormones such as melatonin to induce slumber. The circadian rhythm also controls many other bodily functions including body temperature, hormone production, and organ function.
Irregular sleep patterns over a period of time can lead to circadian rhythm disorders, including shift work sleep disorder. This condition is more common in those working rotating shifts or overnight. Shift work sleep disorder has been shown in research to potentially increase the risk of various types of cancer including prostate, ovarian, colorectal, breast, and lymphoma.
The largest body of evidence to date on the carcinogenic effect of shift work has come from studies on breast cancer in women, mainly in nurses who frequently work night shifts. Exposure to natural or artificial light during night-time hours stops the release of melatonin, a hormone and a powerful antioxidant. Decreased melatonin also increases estrogen, another hormone that has been associated with breast cancer development.
According to the American Academy of Sleep Medicine, about 30% of adults struggle with symptoms of insomnia.  This can include difficulty falling asleep, staying asleep, or poor sleep quality overall. The type of chronic deprivation associated with insomnia can lead to a number of health problems, the most severe of which is cancer.
One observational study on 75,828 postmenopausal women found that too little (< 5 hours) or too much sleep (> 9 hours) increased the risk of colorectal cancer. A similar study of 142,933 postmenopausal women found a significantly higher risk for thyroid cancer in those experiencing insomnia.
Insomnia has been identified as a risk factor for other cancers as well, including breast, prostate, and colorectal. No one knows exactly how insomnia plays a role in cancer development, but some theories include chronic inflammation, insulin resistance, decreased melatonin, or increased cortisol production.
As many as half of all cancer patients experience some form of sleep disturbance, making it one of the most common side effects reported. Trouble falling asleep, frequent rousing in the night, poor overall quality, and early morning waking are all difficulties patients often report. Insomnia can impact those with cancer in a variety of ways contributing to fatigue, altered mood, immunosuppression, decreased quality of life, and possibly even disease progression. 
Many factors contribute to insomnia in those battling this condition. Anxiety about recent diagnosis, pain, hospitalization, and the disease itself can all make sleep more challenging.
Insomnia can also become a vicious cycle when fatigue comes into play. To compensate for lost hours, people tend to go to bed earlier or take frequent naps, making it more difficult to get quality sleep at night.
The circadian rhythm regulates nearly every metabolic function in the body, including digestion, intake of food, detoxification, and storage of fats and sugars. Absorption and metabolism of medication is another job that this biological clock performs.
Scientists have discovered how to use this to their advantage with the creation of novel “chronotherapeutic” medications, regulating the timing of chemotherapy to increase its effect.
Unfortunately, any alteration of the circadian rhythm can also negatively impact treatment making medications like chemotherapy less effective.
Research has also shown that treatment with chemotherapy can lead to disruption of the circadian rhythm. One study of 77 colorectal cancer patients found that nearly half had altered circadian rhythms while being treated with chemotherapy and this also contributed to shorter overall survival. Another study of 436 patients with the same disease subtype had similar results.
Fatigue is one of the most debilitating and common side effects that nearly all cancer patients experience. For many, this persistent lack of energy can follow them for years, even after going into remission. According to Julienne E. Bower, Ph.D. who is part of the Division of Cancer Prevention and Control Research at UCLA, “Cancer-related fatigue causes disruption in all aspects of quality of life and may be a risk factor for reduced survival.” 
Fatigue can negatively affect relationships, mood, work, and nearly every aspect of daily life. At times, fatigue is so severe that it may lead to discontinuation of treatment.
Unlike “normal” fatigue related to lack of sleep or overexertion, cancer-related fatigue is persistent and is not improved by additional slumber or rest. Patients often describe this type of fatigue as feeling weak, tired, or exhausted. Whether their fatigue stems from the disease, treatment, or psychological aspects of chronic illness, nearly all cancer patients report difficulty managing day-to-day life when they are suffering from fatigue.
Most people have experienced the effects of too little rest on their mood and can relate to “waking up on the wrong side of the bed.” When this lack of sufficient rest is ongoing, emotions become difficult to control and it can be nearly impossible to keep a positive mindset.
According to the National Cancer Institute, approximately 15-25% of cancer patients also suffer from depression. Many factors contribute to depression in this population, including “disruption in serotonin/dopamine pathways, experience of loss or anticipated loss, direct side effects of chemotherapy medications, presence of tumors in the central nervous system, poorly managed pain, disruption of sleep due to medical treatments, and anemia.” 
Research has shown that sleep disturbances drive inflammation, both of which are risk factors for cancer and depression. Having any form of chronic illness increases the likelihood of developing depression, and difficulty with sleep is one of the key features of this serious mental health disorder.
Some sobering statistics about cancer and depression include:
According to the American Cancer Society, many causes of pain can negatively affect sleep and quality of life in those battling this condition.
“The cancer itself often causes pain. The amount of pain you have depends on different factors, including the type of cancer, its stage (extent), other health problems you may have, and your pain threshold (tolerance for pain). People with advanced cancer are more likely to have pain. Cancer surgery, treatments, or tests can also cause pain. You may also have pain that has nothing to do with the cancer or its treatment. Like anyone, you can get headaches, muscle strains, and other aches or pains.”
Without adequate rest, many senses are heightened, including pain. Pain can feel more severe without sufficient rest, and it becomes increasingly difficult to cope and remain positive. Scientists believe that “because sleep leads to recovery and repair of tissue and may offer a temporary cessation of the psychologic awareness of pain, poor sleep can lead to decreased capacity to manage pain.”
Opioid medications are often prescribed to manage pain in those with cancer, and one of the most common side effects of these medications is sedation. Unfortunately, rather than improving sleep, opioids decrease REM cycles, alter circadian rhythm, and increase daytime drowsiness, further contributing to the disturbances in sleep that are all too common in those with chronic pain. 
Studies have found that there is a strong correlation between decreased quality of life, poor sleep quality, and pain in patients with cancer.  A study of 102 patients with stage IV cancer looked at how these three factors are interrelated and concluded that “patients with poor quality of life also suffered from greater pain, and poorer quality of sleep.”
Although cancer diagnosis rates have been steadily increasing over the last few decades, long-term survival rates have too. Thanks to earlier detection and advancements in treatment, approximately two-thirds of those diagnosed will become long-term survivors or continue to live with their disease as a chronic illness that is managed using ongoing treatment.
The amount and quality of sleep is an important albeit often overlooked factor that can contribute to cancer prevention and survival.
A Women’s Health Initiative study involving 4,406 women with invasive breast cancer found that poor sleep quality may make cancer more aggressive. Another study using data from 7,500 women with the same diagnosis found that those who slept less than 5 hours a night had a 1.5-fold increased risk of death compared to those that slept 7-8 hours a night.
New research has also shown that a properly functioning circadian rhythm can make treatment more effective, but a disruption may increase the chance of drug resistance. The circadian rhythm plays a role in cell fate, which is why more and more treatments are being timed to increase apoptosis (cell death) of tumor cells.
Dr. Amanda Phipps is an epidemiologist at Fred Hutch Cancer Research Center and identified a link between pre-diagnosis sleep deprivation and increased breast cancer mortality. She believes that the results of her findings may help women with disease prevention.
“[These results] could potentially be empowering,” Phipps said. “Sleep is certainly something that is controllable. We have control over it more than family history of the disease. These results generally suggest that the more attention we give to sleep as an important aspect of overall health, the better we might do for breast cancer patients. Sleep may be something we can encourage and promote to help women diagnosed with breast cancer to improve their overall health and to potentially improve their prognosis.”
While many aspects of living with a diagnosis can seem outside of your control, sleep does not have to be one of them. Better rest can make it easier to cope and remain positive, but it also may improve treatment outcomes and even survival. For those looking to avoid the unwanted side effects that prescriptions for sleeping medications can bring, there are many safe and natural alternatives to improve sleep.
Cognitive behavioral therapy (CBT) is a well-researched treatment for insomnia that can be very helpful for cancer patients. CBT involves working with a therapist over a number of sessions to reframe thoughts and emotions around sleep.
Using mental reframing, negative thoughts about sleep are replaced with positive ones, and patients have the opportunity to develop mindful habits. Deep breathing exercises and progressive relaxation techniques are also used to calm the body and mind.
Acupuncture is a Traditional Chinese Medicine (TCM) therapy that involves placing small, metallic needles in the skin that are manipulated using electrical or hand stimulation. The idea behind TCM is that the body has patterns of energy flow (Qi) that can become blocked, leading to disease.
Acupuncture may work by releasing natural opioids and other peptides in the central nervous system and by impacting neuroendocrine function. It is a widely used therapy for treating nausea and vomiting from chemotherapy or post-operatively and is being used more regularly to treat insomnia as well.
Pain and sleep are very interlinked and can impact one another. Pain during the day can impair sleep that night, and a poor night’s rest can make pain feel worse the next day. For many individuals, proper pain management can be an important element in improving sleep quality.
Treating pain associated with cancer can be done using pharmacologic and nonpharmacologic options. While drowsiness is a common side effect of pain medications, oftentimes the type of rest this brings is not restorative and may further contribute to alterations in circadian rhythm.
Receiving the diagnosis of a major illness can be very scary and bring up many underlying worries and fears. Anxiety and depression are very common in those battling cancer, and counseling is generally recommended to all those newly diagnosed.
Regardless of whether patients are battling mental health issues on top of their disease process, speaking to a therapist can be very helpful. Counseling can help to work through emotions that may be preventing patients from getting good quality rest at night.
Physical touch is not only comforting but can also help by relieving pain and relaxing the body and mind. Many people can attest to the healing power of massage therapy, but it doesn’t take a professional to receive these positive benefits.
Having your partner or loved one give you a massage can be a positive experience for them too! Many family members and friends of those battling cancer often feel helpless despite their desire to provide support. Being able to help in such a tangible way can be just as therapeutic for them as it is for you.
To make the massage even more effective, have your partner use a warm oil such as coconut oil with a few drops of essential oils (use lavender for relaxation or peppermint for any muscle aches). Favorite areas to massage are typically the neck, back, feet, and hands.
According to oncologists from the University of Rochester, “sleep disruptions can persist in cancer survivors for many years after diagnosis and completion of treatment, making it one of the most pervasive problems faced by patients with cancer.” Researchers estimate that between ¼ to ⅓ of survivors continue to experience symptoms for as long as ten years after diagnosis.
With more and more research pointing to the protective health effects of sleep, focusing on this lifestyle factor is now more important than ever.
Going to bed and waking up at the same time every day can help to regulate the circadian rhythm. Performing a bedtime routine every evening can further train the brain that it is time to prepare for sleep. The best pre-bed calming activities are things like yoga, meditation, journaling, or taking a warm bath or a shower.
The best way to maintain health as a survivor is to establish good habits and to stick with them. Try to keep a positive mindset and avoid unnecessary stress in your life. Incorporate activities that are relaxing and bring you joy. Optimism and self-care can go a long way in helping the body to relax and rejuvenate at night.
As long as your doctor has given the okay, daily exercise can be a great way to improve sleep quality along with the many other benefits it provides. Invigorating exercise is best to do earlier in the day to boost energy and stamina but try to avoid these activities 2-3 hours prior to bedtime. Yoga and light stretching are more calming and can be done anytime.
Nicotine (found in cigarettes) and alcohol can both interfere with rest at night and should be avoided for several hours before bed. Nicotine suppresses REM sleep and can disrupt circadian rhythms. While alcohol can make you fall asleep faster, it reduces REM cycles and may cause you to wake feeling unrested.
Napping during the daytime can be very tempting if you are battling ongoing fatigue. Unfortunately, daytime naps can make falling asleep at night more challenging and reduce the overall quality of sleep in general. If you feel you must nap, try to do it earlier in the day and set an alarm for 30 minutes or less.
Both sleep and cancer are incredibly complex and there is still so much we don’t know about the extent of their relationship. While research is ongoing, the knowledge we have gained in this area over the last few years will go a long way in helping with disease prevention and treatment.
The challenges of cancer are difficult enough, and without sufficient rest, it can be hard to cope and remain positive. If you are struggling with sleep, speak to your Oncologist or other health care providers about the treatment options that may be best for you.
Knowledge is one of the most powerful tools we have, and hopefully, you feel more empowered about the impact that sleep can have on your health. As an Irish Proverb says, “A good laugh and a long sleep are the two best cures for anything.”