Cancer pain, fatigue, distress, and insomnia in cancer patients.

Insomnia is common among cancer patients, occurring in approximately 30% to 50% of the cancer population. The interactions between cancer pain, insomnia, fatigue, and depression/anxiety are complex, warranting treatment plans that focus not only on the relief of specific symptoms to improve quality of life but also on the impact of treatment on other related symptoms. Pain is one of the most common symptoms experienced by cancer patients and is one of the primary factors that precipitate insomnia in this population. Fatigue is also commonly reported by cancer patients, with a prevalence of nearly 80% in some tumor types. Cancer-related fatigue occurs most often after surgery, chemotherapy, radiotherapy, or immunotherapy and has been reported by cancer patients to be the major obstacle to normal functioning and a good quality of life. Insomnia in cancer patients often occurs in association with psychological disorders such as depression or anxiety. Sleep disturbances are associated with aberrant patterns of cortisol secretion, such as those found in insomnia, which are known to significantly depress the immune system, particularly the cells of the immune system responsible for mounting a defense against tumors. Evidence suggests that management of insomnia through a combination of pharmacologic and nonpharmacologic means can have a positive impact not only on insomnia but also on related symptoms and, consequently, on overall health and quality of life. Although the treatment of insomnia in cancer patients can improve cancer-related fatigue, immune functioning, and overall quality of life, insomnia in the context of cancer is still undertreated. Physicians should use hypnotic agents appropriately and be aware of the reduced potential for producing tolerance and dependence with the nonbenzodiazepine hypnotic agents. The management of insomnia in cancer patients should include a global treatment plan designed to address not only the underlying sleep disturbance but also the related symptoms that may contribute to insomnia or occur as a result of it.