The findings "point to the fact that sleep, including insomnia symptoms, are a really big problem for cancer patients," said Dr Carol Enderlin, who studies sleep in breast cancer patients at the University of Arkansas for Medical Sciences in Little Rock.
"Many of them may think this is just something they have to deal with," Dr Enderlin, who was not involved in the new research, said.
But the message for patients, she said, is "to be aware of sleep and the importance of sleep, to report changes in sleep to your healthcare provider before they become severe (and) to not be afraid to bring them up."
Cancer and insomnia linked
Canadian researchers, led by Dr Josee Savard of the Laval University Cancer Research Center in Quebec, asked close to 1,000 patients having surgery for cancer whether they had trouble falling asleep at night or staying asleep.
Then, they regularly followed up with the same patients to see if their sleep and sleep symptoms changed over the months after treatment.
Patients were between 23 and 79 years old, and most had early-stage cancers.
At the time of treatment, 59% of patients reported symptoms of insomnia, and about half of those were severe enough to qualify as insomnia syndrome, a collection of persistent symptoms such as requiring more than half an hour to fall asleep at least three nights per week. That rate was three times higher than in patients than in the general population.
A year and a half later, 36% of the participants reported insomnia symptoms.
While patients were generally less likely to report insomnia as time went on, one in seven developed symptoms for the first time in the months after surgery.
Fatigue and cancer
In another study published along with the first one in the Journal of Clinical Oncology, Dr Julienne Bower of the University of California, Los Angeles, and colleagues found that close to two-thirds of recently treated breast cancer patients suffered from fatigue and poor sleep quality.
It's only in recent years that sleep has been recognised as a problem for cancer patients, researchers said.
"There was a shift in attention a decade ago as cancer survivors were living longer," Dr Bower said. "Oncologists were beginning to notice that they actually were having these persistent side effects and symptoms, and fatigue has probably been the most common."
Her research team has been testing the effectiveness of yoga as a treatment for fatigue and tai chi for insomnia. Cognitive behavioural therapy, which has helped other people with insomnia, might also work for cancer patients with fatigue or insomnia, she said.
Dr Enderlin said she hopes doctors and nurses will start routinely asking cancer patients about sleep and addressing sleep-related symptoms.
"When people are faced with stress, when they are faced with challenges, they do much better on a good night's sleep," she said. "It's very important, never more so than with cancer patients."
(Reuters Health, Genevra Pittman, August 2011)