ONS: Cancer Fatigue Is More Than Just Feeling Tired

By John Gever
PHILADELPHIA, 19 may 2008-- Fatigue associated with cancer radiotherapy is more complex than generally recognized and should be thoroughly explored in patients reporting fatigue symptoms, a researcher said here. Patients interviewed after undergoing radiotherapy described three separate categories of fatigue-related effects that need to be evaluated with multiple measures, reported Loretta A. Williams, Ph.D., R.N., of M.D. Anderson Cancer Center in Houston, at the Oncology Nursing Society meeting. Patients should be asked not only about fatigue severity, but also whether it interferes with normal activities, she said.
Dr. Williams pointed out that the percentages of patients reporting some level of fatigue varied considerably with diagnosis. One-quarter of breast cancer patients reported no fatigue compared with 62.5% of those with prostate cancer.
Although fatigue is a well-known effect of radiotherapy and other cancer treatments, it is not well defined, Dr. Williams said.
Standard measurements are often one-dimensional, with patients asked simply if they feel tired. Additional fatigue-related parameters are sometimes explored but these vary considerably with no validated standards.
Moreover, even when multiple dimensions are assessed, the results may end up rolled together into a single composite measure of fatigue, she said.
"The purpose of my research was to try to bring some clarity and understanding to measurement of fatigue in cancer patients," she said. "It is important that we have a clear definition of what fatigue is, and a clear measurement that matches that definition."
Dr. Williams and colleagues interviewed 21 adult patients after they had received 21 to 25 doses of radiation therapy totaling 37.8 to 62.5 Gy and who reported some level of fatigue.
Patients were being treated for prostate, breast, or head and neck cancer. Those undergoing concurrent chemotherapy were excluded.
Interviews lasted about 30 minutes, with patients being encouraged to tell stories about their fatigue-related experiences during radiation treatment.
Transcripts of the interviews were then analyzed by Dr. Williams using a technique called descriptive content analysis to organize patients' descriptions into themes. Her analysis of each interview was then reviewed by two other researchers.
Dr. Williams identified three main themes from the 21 interviews:
Loss of strength or energy
Major effects on daily activities and social interactions
Physical and mental sensations
Patients described loss of strength or energy in terms suggesting feelings of tiredness or weakness, progressing to exhaustion in a minority of cases.
Major effects included lack of motivation or inability to perform usual activities. "Some patients reported becoming so fatigued they couldn't shop for food or couldn't prepare food," she said.
Patients also said talking to other people became difficult. Dr. Williams quoted a breast cancer patient as saying, "It tires me out just having people around."
Another frequently reported major effect was an overwhelming need to rest frequently and/or after performing what they would ordinarily consider a routine task.
Physical sensations associated with fatigue included: feelings of malaise, achiness, being weighted down, and lack of appetite.
Mental sensations included mental distress and difficulty in thinking and concentrating, Dr. Williams said.
She said men were more likely to report mental sensations, whereas physical sensations were more frequently described by women.
"Patients need to be assessed regularly," Dr. Williams said.
In particular, assessments should focus not just on severity but also on interference with normal activities.
She said these assessments could identify patients who need assistance, without which their physical and mental health status may suffer.
Dr. Williams is now studying fatigue associated with chemotherapy. She said about 60 interviews had been conducted to date, with results to be reported later.
The study was funded by Cephalon. No potential conflicts of interest were disclosed.

Primary source: Oncology Nursing ForumSource reference:Williams L, et al "Defining fatigue: The experience of patients with cancer receiving radiation therapy" Oncology Nursing Forum 2008; 35: 488.