Sleep disturbances in cancer patients: Underrecognized and undertreated
ABSTRACTSleep-related complaints are extremely common in patients with cancer but often are not recognized, and even if they are, they are seldom treated. Recognizing insomnia in cancer patients is imperative, as appropriate treatment can improve quality of life.
KEY POINTS
- Sleep disturbances, primarily insomnia, profoundly affect all aspects of quality of life.
- Insomnia can be caused or worsened by a number of other conditions, such as pain, fatigue, depression, and anxiety, and these in turn can be worsened by insomnia.
- Cognitive-behavioral therapy is the treatment of choice for chronic insomnia. Underlying problems should be addressed.
- Drugs are often prescribed to help cancer patients sleep but should be used with caution, as there is limited information from clinical trials in this population.
Many cancer patients don't sleep well, for a variety of reasons. It is an important problem: not only does poor sleep worsen quality of life, it may affect prognosis. Moreover, treatment is available.
Yet many physicians caring for cancer patients do not ask about sleep problems, underestimating their impact or focusing on more urgent problems. Also, patients may not want to bring up the topic because they consider poor sleep to be unavoidable and untreatable and because they fear that reporting it may shift the focus of their treatment from trying to cure the cancer to easing its symptoms.
This practical review will help health care professionals avoid the common barriers to diagnosis and treatment of poor sleep in cancer patients. Because there are few data on other sleep disorders such as sleep apnea and restless leg syndrome, we will focus on the most common one in cancer patients—insomnia—and its effects on other symptoms and quality of life.
MORE PATIENTS SURVIVE CANCER NOW
Today, more patients are surviving cancer, but cancer symptoms and the side effects of surgery, chemotherapy, and radiation therapy may persist for years.1,2 The most common complaints include cancer-related fatigue, leg restlessness, anxiety, insomnia, and excessive sleepiness.3
Sleep disturbances appear to contribute to the other problems and are relatively easier to quantify. Most studies of sleep disorders in cancer patients have looked specifically at insomnia,4 although a few have explored the prevalence of other sleep disorders, such as sleep-disordered breathing and limb movements during sleep.5
The International Classification of Sleep Disorders, 2nd edition,6 defines insomnia as difficulty going to sleep or staying asleep (the latter defined as waking up in the middle of the night, with wakeful episodes lasting more than 30 minutes), early-morning awakenings (waking 30 minutes or more before the intended time), or nonrestorative sleep, causing significant distress or impairment of day-time functioning.
INSOMNIA WORSENS QUALITY OF LIFE
Insomnia significantly worsens quality of life in cancer patients, and if it can be detected and effectively treated, quality of life is likely to improve. Studies in cancer patients have found that those with insomnia:
- Were less able to cope with stress and carry on their activities of daily living3
- Were much less able to function and reported more pain, less energy, and greater difficulty in dealing with emotional problems7
- Had poor quality of life, both physically and emotionally.3,8
PERHAPS MORE THAN HALF OF CANCER PATIENTS HAVE INSOMNIA
Depending on the methods used and populations studied, at least 30% and perhaps more than half of patients with cancer have insomnia (Table 1).3,4,8–14 It is one of the most commonly reported complaints in this group,15–17 and it occurs before, during, and after treatment of cancer.
Although the prevalence may differ in various cancers, it is still higher than in the general population. In a study of about 450 patients with cancer or depression and 300 healthy volunteers, 62% of the cancer patients reported moderate to severe sleep disturbance, compared with 52% of the depressed patients and 30% of the healthy volunteers.18
When Davidson et al3 surveyed nearly 1,000 cancer patients, one-third said they had insomnia. The problem was most prevalent in lung and breast cancer patients.
In a longitudinal study by Savard et al,13 the prevalence of insomnia declined over time but remained high even at the end of 18 months. It was more prevalent in patients with gynecologic and breast cancer than in those with prostate cancer.13,19
SLEEP PROBLEMS ARE UNDERREPORTED
Sleep problems in cancer patients often go unrecognized because patients do not report them. In a survey of 150 patients,20 44% reported having had sleep problems during the preceding month. However, only one-third of those with sleep problems told their health care providers. This highlights the need for physicians to address sleep complaints in cancer patients at every visit and, if needed, to refer them to a sleep specialist for further evaluation and management.
INSOMNIA IS OFTEN ASSOCIATED WITH OTHER PROBLEMS
Many things can interfere with sleep in cancer patients: the cancer itself (eg, pain due to tumor invasion), medical treatments (eg, narcotics, chemotherapy, neuroleptics, sympathomimetics, steroids, sedative hypnotics), psychosocial disturbances (eg, depression, anxiety, stress), and comorbid medical issues.
In this population, insomnia is often part of a cluster of symptoms that includes pain, fatigue, depression, and anxiety. These act synergistically, worsening quality of life.21–24
