Determinants of chronic fatigue in disease-free breast cancer patients: a cross-sectional study.

BACKGROUND: Quality of life after cancer treatment becomes more important as the number of long-term survivors increases. This study aimed to investigate complaints of fatigue after treatment for breast cancer. PATIENTS AND METHODS: The study patients were 150 women who had finished curative treatment for breast cancer by a mean of 29 months before commencement of this study. Measurements included computerised questionnaires and a daily Self-Observation List.
RESULTS: Thirty-eight per cent of the sample were severely fatigued, compared with 11% in a matched sample of women without a history of cancer. No association was found between fatigue and former treatment. The 'severely fatigued disease-free breast cancer patient' scored more 'problematic' on psychological well-being, functional impairment, sleep disturbance, physical activity, social support, neuropsychological and social functioning compared with the 'non-severely fatigued disease-free breast cancer patient'. Furthermore, the severely fatigued patients had a lower sense of control with respect to their fatigue complaints and stronger breast cancer- and psychologically-related attributions with regard to the causes of fatigue compared with the non-severely fatigued patients. Regression analyses indicated that sleep disturbance, physical activity and causal attributions contributed significantly to the subjective experience of fatigue.
CONCLUSIONS: Severe fatigue is a problem for almost 40% of the sample of breast cancer survivors. Severe fatigue is related to physical, psychological, social, cognitive and behavioural factors.