Sleep Quality & the Cancer Journey
Increasing emphasis on co-managing sleep disorders in oncology
March 6, 2014
Sleep disturbances and fatigue are among the top quality of life complaints for patients with cancer, yet the issues are rarely discussed during oncology visits.
"Understandably, survival is the top priority for patients with cancer," explained Diwikar Balachandran, MD, medical director, sleep center, division of pulmonary medicine, The University of Texas MD Anderson Cancer Center, Houston, Tex. "When patients hear they have cancer, the fear of immediate death is high. Discussing sleep quality gets ignored. Yet, when you do quality of life instruments in these patients, sleep quality isn't high."
Because of the growing body of literature on the connection between sleep disorders and cancer outcomes, Balachandran decided to lead the team opening MD Anderson's Sleep Center in 2006. At the time, the goal was to open a sleep center so other cancer centers could focus on surgery and treatment.
Patients complaining of insomnia or daytime sleepiness can be referred to MD Anderson's sleep clinic. According to Balachandran, the facility is instituting screening measures for sleep apnea for patients undergoing surgery as well as possible partnerships for head and neck cancer screening.
Concurrently, there's a gradual acknowledgement of the connection between cancer and sleep problems. According to the National Cancer Institute, 45% of cancer patients experience sleep problems. University of California at San Diego has a sleep lab on campus as does Cancer Treatment Centers of America's Eastern Regional Medical Center and more are emerging. Anne Malone Berger, PhD, APRN, AOCS, FAAN, conducted groundbreaking research at University of Nebraska Medical Center as PI of a NIH/NINR study on sleep. At the last national meeting of the American Academy of Sleep Medicine, a symposium was introduced on cancer and sleep, definitively placing the issue on the national radar.
Though sleep problems are so common among cancer patients, the degree may vary depending on the patient's age, the kind of cancer and the stage of the disease.
Those with end-stage cancer frequently have sleep issues, noted Balachandran. Patients with head, neck or lung cancer are proven to be at a high risk for sleep disordered breathing.
Recent research suggests age may play a role. MD Anderson conducted a study stratifying patients by age. Older patients had more arousals and less REM or deep sleep.
"It was very interesting that these older patients were less likely to complain," he said. "Younger patients had better quality sleep with fewer disturbances but many more complaints. Even when compared with normal age controls, the (older) patients with cancer had even more disturbances."
Furthermore, more men than women have sleep apnea. As they approach menopause, women's rates escalate to reach their male counterparts, said David Visco, MD, FCCP, pulmonologist, Eastern Regional Medical Center in Philadelphia.
Visco uses his encounters with lung cancer patients especially as an opportunity to test for underlying sleep disorders. Many patients are surprised to learn they've had sleep apnea long before they were diagnosed with cancer.
"You may have sleep apnea, but be getting along just fine," Visco said. "Suddenly, you're diagnosed with cancer and all you want to do is nap. The underlying sleep disorder becomes unmasked. People feel a whole lot better when their sleep apnea is treated with their cancer. Nobody knows if there's a cause-effect relationship, but I'd like to think it makes chemotherapy tolerance better.
Another subset of Visco's patient population had sleep apnea diagnosed years ago, but never had a follow-up study.
Other risk factors for sleep apnea include hypertension, depression, obesity and heart disease. It's an important distinction when considering the high numbers of cancer survivors who still suffer from sleep apnea.
"People think of patients with cancer as being skeletally thin but patients with breast cancer gain weight through hormone replacement therapy," Balachandran said. "These patients are predisposed to worsened daytime function and alertness."
Pharmacological & Behavior Modification
Patients referred to a sleep center stay overnight and have sensors attached to a monitor. Digital monitoring devices record the level of sleep and measure brain waves, eye movements, muscle tone, heart rate, respiration, blood oxygen levels and more.
If abnormalities are detected, the technologist will apply a breathing mask to find the treatment level. Sometimes this cannot be done in the same night, so an additional study may be necessary.
Currently, MD Anderson Cancer Center and Cancer Treatment Centers of American in Philadelphia perform polysomnography. In this study, sensors on the patient's scalp, temples, chest and legs are connected by wires to a computer. The wires are long enough to allow normal movement in bed. A small clip also is placed on the finger or ear to monitor the level of oxygen in your blood. Polysomnography measures brain waves, eye movements, heart rate, breathing pattern, blood oxygen level, body position, limb movement as well as Snoring and other noises on a continuous graph.
Getting the results is the easy part. Implementing the right treatment plan can be a challenge.
"We're big believers in changing behaviors, using relaxation techniques, and non-pharmocologic measures early and first," said Balachandran. "The results of these interventions are longer lasting. Zolpedim and eszopiclone may be great for 3-6 months."
In the short-term, although there's no "magic pill" for insomnia, Balachandran said pharmacologic are acceptable for acute events, like chemotherapy or cancer related pain keeping patients up at night.
For sleep apnea, Visco uses the Epworth Sleepiness Scale and send an in-home monitoring device home with patients. Continuous positive airway pressure machines are most effective for sleep apnea. Patients with restless leg syndrome usually are treated with a prescription and behavior interventions are the usual remedy for insomnia.
It may be tempting to write off sleep interventions as an extra in cancer treatment, but the evidence is pointing otherwise.
The University of Wisconsin Sleep Cohort released the first human study associating sleep apnea with higher mortality in cancer last year.
"Clearly, there is a correlation, and we are a long way from proving that sleep apnea causes cancer or contributes to its growth," said F. Javier Nieto, MD, MPH, PhD, chair of population health sciences at University of Wisconsin.. "But animal studies have shown that the intermittent hypoxia (an inadequate supply of oxygen) that characterizes sleep apnea promotes angiogenesis-increased vascular growth - and tumor growth. Our results suggest that SDB is also associated with an increased risk of cancer mortality in humans."
These results aren't surprising to Visco, who has seen the anecdotal evidence in his clinic over the years.
"If you deprive humans of sleep, we're subjected to the co-morbidities that follow," he said. "We have enough data on sleep deprivation and its effect on cardiovascular systems and metabolic risk, so it's not surprising that cancer would fall in the same line."
Robin Hocevar is on staff at ADVANCE. Contact: firstname.lastname@example.org