To determine the prevalence of cancer-related fatigue syndrome (CRFS) in a population of disease-free breast cancer survivors and to investigate the relationship between CRFS and clinical variables.
Patients and methods
Women (200) were recruited. All participants were between 3 months and 2 years after completion of primary therapy for breast cancer and were disease free. Subjects completed a diagnostic interview for CRFS and structured psychiatric interview. Participants also completed quality of life, mood and fatigue questionnaires, and provided a blood sample for haematological and biochemical analysis and a 24-h urine specimen for cortisol estimation. Subjects wore a wrist actigraph for 7 days to measure activity and sleep.
Results
Sixty women (30% of participants) were found to fulfil the criteria for CRFS. There were statistically significant differences between fatigued and non-fatigued women with respect to fatigue severity (p < 0.01), mood (p < 0.01) and quality of life scores (p < 0.05). There were significant differences in blood variables including raised total white cell count and lower sodium (all p < 0.02). There was no difference in the 24 h urinary free cortisol levels. Actigraphic data demonstrated significant differences in sleep quality and disturbance, but not in overall levels of daytime activity or circadian rhythm.
Conclusion
CRFS affects 30% of women after breast cancer treatment and has significant effects on quality of life and mood. There is some evidence that CRFS is related to sleep disturbance or to a persistent inflammatory or immune response.