The relationship of fatigue in breast cancer survivors with quality of life and factors to address in psychological interventions: A systematic review.

Severe fatigue occurs in one in four breast cancer survivors (BCS). Quality of life (QOL) and psychological factors are important in fatigue-oriented interventions for BCS, but an up-to-date overview is lacking. The aims of this review were to (i) provide a comprehensive overview of the relationship of fatigue with QOL and factors that can be addressed in psychological interventions for fatigue in BCS and (ii) determine the strength of evidence for these relationships. A systematic literature search was conducted to find studies on fatigue in BCS who had completed curative breast cancer treatment. Fatigue-related factors of 57 eligible studies were extracted and the level of evidence was determined. Factors regarding QOL (ie, general QOL, functioning, work ability, and mental health) had a negative relationship with fatigue (moderate to strong evidence). Target factors for psychological interventions were divided into the subcategories emotional problems, sleep disturbances, physical activity, pain, coping with cancer, dysfunctional cognitions, and social support. Moderate to strong evidence appeared for a relationship of fatigue with depressive symptoms, anxiety, distress, sleep disturbances, lower physical activity levels, pain, difficulties with coping with cancer, and catastrophizing about symptoms. These factors are points of attention for existing and future psychological interventions for fatigue in BCS.