Cancer-related fatigue and functional impairment - Towards an understanding of cognitive and behavioural factors.

Objective: Fatigue is a highly prevalent and debilitating problem in women with breast cancer. This study investigated the cognitive, behavioural, interpersonal and affective responses associated with fatigue and functional impairment for women with breast cancer undergoing chemotherapy. A nested prospective study examined factors predictive of cancer-related fatigue after three cycles of chemotherapy.

Method: 159 women with breast cancer who were about to begin or undergoing chemotherapy completed a range of measures. Correlational and multiple regression analyses explored associations between fatigue severity, functioning and a range of psychological, behavioural, demographic and clinical variables. Forty-two patients were followed-up prospectively to examine the relationship between psychosocial variables, fatigue and functioning after three cycles of chemotherapy.

Results: A range of cognitive, behavioural and affective variables were associated with increased fatigue severity and poorer functioning. Key cognitive and behavioural correlates included, all-or-nothing behaviour, avoidance behaviour, cancer-related catastrophising and critical/punishing responses from others. For the women in the nested prospective study, fatigue significantly increased after three cycles of chemotherapy. Increased fatigue was predicted by increased anxiety before starting chemotherapy.

Conclusions: Behavioural factors and cancer-specific cognitions make important contributions to cancer-related fatigue and associated impairments. Such factors are potentially amenable to change within the context of cognitive behavioural therapy.