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.