medwireNews: UK study results show that over a third of breast cancer survivors (BCS) have cancer-related fatigue syndrome (CRFS) and that these women have significantly lower subjective quality of life and mood than their nonfatigued peers.
Identifying BCS who have or are at risk for CRFS should be incorporated into routine practice and might include counseling on potential cognitive and sleep changes, suggest the researchers.
Ollie Minton (University of London) and co-workers also found significant differences in the average daytime epoch activity (measure of movement intensity) and duration of daytime activity in "light" hours between BCS with CRFS and those without, with the former having significantly lower measures.
"The decreased activity may be a direct consequence of feeling subjectively fatigued, or the decreased activity may arise first (due to a variety of causes) and may be a causative factor in exacerbating or perpetuating the subjective fatigue that these patients experience," writes the research team in BMJ Supportive and Palliative Care.
Women with CRFS also had a significantly higher prevalence of insomnia, despite there being no difference in sleep actigraphy measurements between them and the group without CRFS.
"These findings raise important questions about the nature of CRFS and its relationship to objective deficits in activity and cognition," say Minton et al.
Of the 114 women in the study, 45 (39%) were diagnosed with CRFS according to the four requisite diagnostic criteria.
Participants underwent a Structured Clinical Interview to obtain Diagnostic and Statistical Manual-IV diagnoses, completed questionnaires including the Functional Assessment of Cancer Therapy and Chalder Fatigue Scale, and undertook objective cognitive testing using tools such as the Affective Go No-go (AGN) test.
The women also wore an Actiwatch AW4 (CamNtech, Cambridge, UK) for 7 days and nights to record activity and sleep levels, and circadian rhythm.
Levels of fatigue, mood disturbance, and quality of life were significantly higher, higher, and lower, respectively, in women with CRFS than those without, report the researchers, and outcomes of symptom subscales including the European Organisation of Research and Treatment of Cancer Quality of Life Questionnaire were also significantly worse among the former group.
Mean total commissions (ie, incorrect responses) on the AGN were significantly higher among CRFS BCS, at 7.76 versus 6.57 in the non-CRFS group, indicating poor executive function.
Minton and co-investigators suggest that the lower cognitive function and daily activity in the CRFS group should be examined longitudinally in future studies.
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