The prevalence of insomnia in cancer patients receiving chemotherapy is far greater than has been thought. That was the conclusion of a subset analysis from a large prospective study by researchers at the University of Rochester.
In the study, published in the January 10 issue of the Journal of Clinical Oncology, insomnia was more than twice as common in patients undergoing chemotherapy compared with the general population.
During the seventh day of the first cycle of chemotherapy, 37% of patients (301 patients) reported symptoms of insomnia and 43% (362) met the diagnostic criteria for having insomnia syndrome; 60% of those patients reported that their insomnia symptoms remained unchanged from the first to the second cycles of chemotherapy.
The total number of study patients experiencing insomnia symptoms or having insomnia syndrome, 80%, is two to three times higher than in the general population, said the authors, led by Oxana Palesh, PhD, Research Assistant Professor in the Departments of Radiation Oncology and Psychiatry at the Medical Center and the James P. Wilmot Cancer Center.
“Insomnia is prevalent, under-recognized, under-managed, and understudied among patients with cancer receiving chemotherapy.”
Other findings: Among the total of 823 patients with cancer (mean age of 58, range of 22 to 93), those younger than 58 were significantly more likely to experience either symptoms of insomnia or insomnia syndrome; and patients with breast cancer had the highest number of overall insomnia complaints.
Those with insomnia complaints also had significantly more depression and fatigue than good sleepers, Dr. Palesh said in a follow-up telephone interview.
“Insomnia needs to be treated independently from fatigue and depression. We can't treat other symptoms and hope insomnia will be completely alleviated.”
There are effective treatments, both pharmacological and psychological, and insomnia should be treated before it becomes a chronic condition, she said.
Data from Antidepressant Study
The data on insomnia were taken from a study on the antidepressant paroxetine for management of depression and fatigue in chemotherapy patients treated between 1997 and 1999. That study (JCO 2003;21:4635-4641) was led by Gary R. Morrow, PhD, Professor in the Departments of Psychiatry and Radiation Oncology, the senior author on the new study.
Dr. Palesh explained that the definitions for insomnia symptoms and syndrome used in that study relate to frequency and duration. The syndrome comprises difficulty sleeping three or more times a week for at least a month, and daytime tiredness and fatigue also meet the criteria. Symptoms are having difficulty sleeping but with less frequency and duration.
Portions of the report were presented at two meetings in 2008, and since then have been refined to add the prevalence of insomnia by race. In addition, the authors added a comprehensive summary of insomnia by various depression and fatigue measures.
Two Unexpected Findings
The study showed two unexpected findings, Dr. Palesh said. One was that men and women had an equal incidence in this study, compared with the general population in which women report more insomnia problems. She speculates that the type of cancer and the type of chemotherapy trump some predisposing factors such as gender.
And patients no more than 58 years old had more insomnia than older patients, whereas in the general population older patients are more prone to insomnia. “Perhaps [the age anomaly] is due to more aggressive treatment for cancer types that occur in younger patients,” Dr. Palesh speculated.
It might also be that younger patients have more psychological difficulty adjusting to sleep difficulties. “Older people might have more accommodation for their sleep difficulties,” she said. “When they have a diagnosis of cancer, they already have skills in place to manage insomnia.
“But when younger are diagnosed with cancer there are usually no symptoms yet, so going from health and high functioning to receiving treatment and feeling very sick is a big stressor, so perhaps younger patients have better expectations for better functioning compared with older patients.”
More Stress for Younger Patients?
David Spiegel, MD, an expert on stress and health in cancer patients, asked to comment on the study, speculated that younger patients might have reported more episodes of insomnia because a cancer diagnosis at a younger age occurs at a time in life when it is most destructive.
“The younger patient might be working, and dependent children could still be in the house,” said Dr. Spiegel, Professor in the Departments of Psychiatry & Behavioral Science at Stanford University School of Medicine and Director of the Center on Stress and Health.
As for the question of incidence by gender in this study, Dr. Spiegel was quite candid about just how stoic men are: “Men are usually less open about their symptoms than women, until a major illness strikes and they become more dependent and complaining than women. Men either tough it out or they collapse, while women tend to just cope.”
This study might have included “a group of very sick men who can't fake it anymore and are more open about their symptoms” such as insomnia, he said.
The study data were collected 10 to 12 years prior to this publication, and Dr. Spiegel was asked if any factor might have changed in that time.
He said patients in the study were most likely receiving cytotoxic chemotherapy, whereas today many receive noncytotoxics.
“The biological drugs used today are generally better tolerated and have fewer physiological effects, and the incidence of insomnia today may be somewhat lower than it was 10 years ago,” Dr. Spiegel speculated. But he added that hormonal drugs used today are associated with their own sleep problems.
And even if chemotherapy regimens today have fewer side effects, the stress of having a life-threatening illness is still there.
Dr. Spiegel said a great deal of research has focused on side effects related to cancer chemotherapy, such as nausea, vomiting, and fatigue, “but we've tended to pay less attention to the psychological and psychiatric effects of treatment, and they are also very real.”
‘More Awareness Needed’
In an ASCO news release about the study, Sarita Dubey, MD, a member of ASCO's Cancer Communications Committee, said that it is clear that this is an area where more awareness is needed so patients can get the additional help they need.
“Insomnia has real and potentially serious implications for patients’ quality of life,” continued Dr. Dubey, a head, neck, and lung cancer specialist at the University of California, San Francisco Medical Center. “The study highlights the fact that it's very common among patients undergoing active cancer treatment and is likely not adequately recognized in clinical practice.”