Cancer and Sleep (Part 1): Why Treatment and Recovery Disrupt Sleep
Sleep trouble is one of the most common (and least discussed) effects of cancer and its treatment.
When someone is facing cancer, the list of worries is endless: scans, appointments, treatment decisions, side effects, all the regular stresses and tasks of life, the people they love, and and and. Sleep rarely makes it to the top of that list. And yet, for many people, it quietly shapes how they feel about everything else. (If you've ever tried to face a hard day on a few hours of broken sleep, you know exactly what I mean—literally everything is more difficult literally and emotionally.)
This two-part series is for anyone whose sleep has been disrupted by cancer or its treatment, as well as the family and friends who care about them. In Part 1, we'll look at why and how this happens. In Part 2, we'll look at what can help.
How Common Is Sleep Trouble With Cancer?
A 2022 systematic review and meta-analysis pooled data from 160 studies and over 46,000 patients and found an overall prevalence of sleep disturbance of 60.7%. (Al Maqbali et al., 2022) The National Cancer Institute (NCI) describes insomnia as the most common sleep disturbance among people with cancer, most often arising from physical and/or psychological factors related to the cancer or its treatment (PDQ Supportive and Palliative Care Editorial Board, n.d.-a). In plain terms, if your sleep has fallen apart, you are in good company. Unfortunately, it also means this deserves far more attention than it often gets. A 2020 review of insomnia in women with breast cancer noted that, despite how common and impactful it is, insomnia is rarely addressed systematically in oncology care. (Kwak et al., 2020)
Why Cancer and Its Treatment Disrupt Sleep
There is rarely one single cause. More often, several factors compound one another, which is part of why the problem can feel so stubborn. And, while it can be difficult to untangle the spiderweb of issues that affect poor sleep, there are some major sources that researchers have identified.
1. The Treatments and Their Side Effects
Surgery, chemotherapy, and radiation can each affect sleep in different ways. Research on insomnia in breast cancer for example, points to pain and discomfort from localized therapies (surgical or otherwise) as one of the contributors (Kwak et al., 2020). The National Cancer Institute also lists corticosteroids, which are sometimes used alongside cancer treatment, among the common causes of insomnia in people with cancer (PDQ Supportive and Palliative Care Editorial Board, n.d.-b). A number of medications are also widely known to disrupt healthy sleep across many patient populations. Add in nausea, neuropathy, unfamiliar hospital rooms, and a calendar full of appointments, and it isn't hard to see how a good night's sleep becomes a long shot.
2. Hormone-Related Changes and Hot Flashes
Some cancer treatments, including endocrine therapies used in breast cancer, bring on hot flashes and night sweats, and some medicines can even trigger early menopause (DePolo, 2023). Hot flashes and night sweats are among the factors that contribute to insomnia in women with breast cancer (Kwak et al., 2020) and beyond. If this sounds familiar, I wrote about how shifting hormones affect rest in my article on menopause and sleep, and many of the same dynamics apply here.
3. Stress, Worry, and a Mind That Won't Power Down
Anxiety and depression are common and understandable responses to a cancer diagnosis, treatment, and hospitalization, and the NCI notes that they are highly correlated with insomnia (PDQ Supportive and Palliative Care Editorial Board, n.d.-a). Fear of recurrence is another well-documented contributor (Kwak et al., 2020). Nighttime has a way of amplifying all of this. The distractions of the day fall away, the house gets quiet, and the mind begins to swirl with thought. And then, as so often happens with insomnia, a second layer appears: worry about not sleeping. (“If I don't fall asleep soon, tomorrow will be miserable.” “I need this sleep, why am I still awake!”) That worry is itself activating, which makes sleep even more elusive.
4. A Body Clock Thrown Off Course
Your circadian rhythm is the internal clock that tells your body when to be alert and when to wind down, and it relies on regular cues like light, activity, and meals. A 2022 review in Frontiers in Oncology describes circadian rhythm disruption as an emerging mechanism that may help explain a cluster of common cancer and treatment related symptoms, including fatigue, sleep difficulties, depressive symptoms, and cognitive impairment (Amidi & Wu, 2022). Researchers are still working out exactly how this plays out, but it fits what many people describe. When days are scrambled by treatment schedules, rest, and recovery, and nights are broken up with symptoms, the body's internal clock can easily blur.
5. A Cluster of Symptoms, Not Just One
That same review makes another important point: these symptoms don't operate in isolation. They tend to occur together, can intensify one another over time, and may persist long after treatment is complete (Amidi & Wu, 2022). Poor sleep deepens fatigue. Fatigue changes how active you are and how much you nap. Those changes can further disrupt the next night. And a tired, foggy, discouraged mind has less to work with.
Sleep trouble that begins with treatment can persist well into recovery.
Why It Can Linger After Treatment
Many people assume that sleep will bounce back once treatment ends. For a lot of people, it doesn't. In a randomized trial of insomnia treatment in people with cancer, participants had completed their primary treatment at least a month before enrolling in the trial, and the average time since their cancer diagnosis was nearly four years—yet they were still struggling with insomnia (Garland et al., 2014).
There are a few reasons this can happen. Some of the physical contributors, such as hot flashes from ongoing hormone therapy, don't go away when other treatment ends. The worry doesn't necessarily switch off either (follow-up scans, fears of remission, struggles with identity and much more can last for years). Likewise, learned habits can present a massive roadblock to good sleep as well. After months of lying awake in bed, tossing, turning, and worrying, the brain can begin to associate the bed with wakefulness and distress rather than rest. That pattern can keep insomnia going long after the original cause has faded, which is one of the reasons an approach like cognitive behavioral therapy for insomnia (CBT-I, which targets those learned patterns directly) can be so effective. We'll get into that in Part 2.
Why Sleep Matters
The last thing anyone needs is one more thing to feel anxious about. But, sleep disturbance is not a minor inconvenience. Researchers describe it as one of the most common and troubling symptoms for people with cancer, one that can harm quality of life throughout all phases of treatment and stages of illness (Al Maqbali et al., 2022). The same cluster of symptoms (fatigue, poor sleep, low mood, mental fog) can reduce quality of life and persist long after treatment ends (Amidi & Wu, 2022).
In other words, sleep isn't a luxury to get to once everything else is handled. It's foundational infrastructure for the rest of your recovery. When sleep is off, almost everything else feels harder: coping, concentrating, even hope. That is exactly why it's worth taking seriously, and why it's worth seeking help for.
Adam Scheldt is a sleep counselor, coach, and educator based in Kenmore, New York, serving clients in person and online.
A Closing Thought
If cancer or its treatment has taken your sleep along with so much else, I hope this article offers a sense of relief and validation. It's also something worth talking about. Please consider mentioning your sleep to your oncology team (and don't wait until it's unbearable). Because sleep trouble has so many possible contributors, from pain to hot flashes to medications to worry, your team can help sort out what's driving it for you.
In Part 2, we'll turn to what can actually help, including an approach with strong research support. And as always, I am here to help you explore the landscape of your sleep and get the rest you deserve.
Be well.
References
Al Maqbali, M., Al Sinani, M., Gleason, A., & Alsayed, A. (2022). Prevalence of sleep disturbance in patients with cancer: A systematic review and meta-analysis. Clinical Nursing Research, 31(6), 1107-1123. <https://doi.org/10.1177/10547738221092146>
Amidi, A., & Wu, L. M. (2022). Circadian disruption and cancer- and treatment-related symptoms. Frontiers in Oncology, 12, Article 1009064. <https://doi.org/10.3389/fonc.2022.1009064>
DePolo, J. (2023, June 28). NAMS releases statement on non-hormone therapy for hot flashes, night sweats. Breastcancer.org. <https://www.breastcancer.org/research-news/non-hormone-therapy-hot-flashes>
Garland, S. N., Carlson, L. E., Stephens, A. J., Antle, M. C., Samuels, C., & Campbell, T. S. (2014). Mindfulness-based stress reduction compared with cognitive behavioral therapy for the treatment of insomnia comorbid with cancer: A randomized, partially blinded, noninferiority trial. Journal of Clinical Oncology, 32(5), 449-457. <https://doi.org/10.1200/JCO.2012.47.7265>
Kwak, A., Jacobs, J., Haggett, D., Jimenez, R., & Peppercorn, J. (2020). Evaluation and management of insomnia in women with breast cancer. Breast Cancer Research and Treatment, 181(2). <https://doi.org/10.1007/s10549-020-05635-0>
Mustian, K. M., Sprod, L. K., Janelsins, M., Peppone, L. J., Palesh, O. G., Chandwani, K., Reddy, P. S., Melnik, M. K., Heckler, C., & Morrow, G. R. (2013). Multicenter, randomized controlled trial of yoga for sleep quality among cancer survivors. Journal of Clinical Oncology, 31(26), 3233-3241.
PDQ Supportive and Palliative Care Editorial Board. (n.d.-a). Sleep disorders (PDQ®): Health professional version. National Cancer Institute. <https://www.cancer.gov/about-cancer/treatment/side-effects/sleep-disorders-hp-pdq>
PDQ Supportive and Palliative Care Editorial Board. (n.d.-b). Sleep disorders (PDQ®): Supportive care, patient information. National Cancer Institute. <https://www.columbiadoctors.org/health-library/nci-pdq-cancer/sleep-disorders-pdq-supportive-care-patient-information-nci/>