Oncologists recognize fatigue as being one of the most common complaints from cancer sufferers. Moreover, fatigue is one of the symptoms that cancer patients are most concerned about.
Less understood are the various elements of fatigue, including psychological factors (stress, anxiety, depression), physiological factors (menopause, anemia, pain), and chronobiological factors (disorder of sleep and circadian rhythm patterns).
What is becoming more clear is the relationship between fatigue and sleep. Contrary to the popular belief, increased levels of fatigue can actually increase sleeping problems. Despite this evidence cancer patients are rarely consulted or treated for sleep problems.
Insomnia is diagnosed through a patient's difficulty to both fall and stay asleep, which results in degradation of their functioning during the day. These are the most common complaints that cancer sufferers have about sleep, therefore it can be deduced that they suffer from insomnia.
Insomnia puts cancer patients at higher risk of the disease itself. Tumors that bring about an increase in steroid production, the pain that tumors cause, and general nausea will combine to make insomnia worse.
Patients can have effects making insomnia worse even through the treatment of cancer. Treatment can involve wild fluctuations in hormonal levels, medications can have varying detrimental effects on sleep, and periods of chemotherapy will bring about greater fatigue.
Environmental factors such as too much light and noise in the bedroom (during medication, for instance) will also have a general disturbing effect on a patient's sleep. And, of course, there is an increased level of psycho-social and comorbid medical disorders such as depression, stress, anxiety, headaches, all of which make for poor sleep patterns.
One study has concluded that 52% of all cancer survivors reported some sort of difficulty with sleep during their illness. Although 66% of them admitted that their insomnia had started prior to their cancer diagnosis, 58% stated that the cancer had aggravated their sleep issues.
These results suggest that there is a negative feedback loop in which the challenges of cancer lead patients to developing insomnia. Thus insomnia worsens the medical conditions that exist with the cancer.
So there is an opportunity to break this cycle by treating insomnia. Of course, identifying the problem is important. Sleep disorders should be considered one of the symptom clusters linked to cancer.
The concept of symptom clusters is not new in treating cancer. Liu et al's study examined one symptom cluster comprising of suboptimal sleep, depression, and fatigue. The results found that the more of this cluster the patients experienced prior to chemotherapy, the worse the symptoms were during chemotherapy. Patients with more severe and frequent symptoms prior to chemotherapy experienced the highest severity of symptoms during treatment.
Several studies have shown, however, that a high percentage of cancer patients fail to mention their sleep problems. Almost 80% assume that their cancer treatment is causing the sleep disorders. 60% of patients wrongly assume the symptoms to be temporary, while around 50% believe that doctors can do nothing to help their conditions.
This is clear evidence that clinicians should include sleep in the recognized cancer symptom cluster and ask each patient about their sleep. Posing the simple question 'What is your sleep like?' Can identify and address this important issue.
Why is treatment of insomnia so important? Well, insomnia contributes to a range of issues that affect a patient's quality of life and can influence the course of cancer. Such issues include: mood disturbances, severe fatigue, and immunosuppression. Clinicians need to be asking themselves what is the best way to treat insomnia in their cancer patients.
Treatment of insomnia in this patient group may require a multimodal approach as there are a variety of causes. Treatment should be both pharmacological (benzodiazepine or melatonin receptor agonists) and include nonpharmacological therapies.
A statement on insomnia made by the national institutes of health at their 2005 State-of-the-Science Conference concluded that the most effective treatments for insomnia are behavioral therapies. This backs up several studies stating that cognitive behavioral therapy (CBT-I) is an effective treatment for insomnia in cancer patients.
All of these studies concluded that CBT-I improved the time spent sleeping, helped raise people's total sleep time, reduced fatigue, improved mood and general quality of life. The therapeutic effects of CBT-I were maintained at 3, 6, and 12 month followup periods.
One of the innovative features implemented in Berger et al’s study into this therapy was that CBT-I was initiated before the cancer patients had developed any sleeping disorder or fatigue.
Results indicate that despite sleep being improved at 90 days before chemotherapy in the group administered CBT-I compared to the studies that began treatment after chemotherapy to patients with insomnia, any differences between the groups had disappeared at 12 months.
The conclusion of Berger et al. was that clinicians should identify and intervene with CBT-I at the point when cancer patients report insomnia ranging from moderate to severe. The other key message was that treatment started during chemotherapy may only have short-term benefits and require additional treatment after chemotherapy.
Berger et al's assumption that clinicians should enquire about patients' sleep and initiate treatment when an issue is identified is correct.
Summary
Insomnia is common in cancer patients. Patients' sleep should be assessed so that their quality of life, and possibly the course of the cancer, can be improved.
A variety of pharmacological and nonpharmacological therapies exist for managing cancer related insomnia. However, for them to be effective, clinicians must identify insomnia by communicating with patients and be willing to start an appropriate treatment. If so, we can improve the quality of life for cancer patients during and after their treatment.
