Do all patients with cancer experience fatigue? A longitudinal study of fatigue trajectories in women with breast cancer.

BACKGROUND: Fatigue is a common and expected side effect of cancer treatment. However, the majority of studies to date have focused on average levels of fatigue, which may obscure important individual differences in the severity and course of fatigue over time. The current study was designed to identify distinct trajectories of fatigue from diagnosis into survivorship in a longitudinal study of women with early-stage breast cancer. METHODS: Women with stage 0 to stage IIIA breast cancer (270 women) were recruited before (neo)adjuvant therapy with radiotherapy, chemotherapy, and/or endocrine therapy and completed assessments at baseline; posttreatment; and at 6 months, 12 months, and 18 months of follow-up. Growth mixture modeling was used to identify trajectories of fatigue, and differences among the trajectory groups with regard to demographic, medical, and psychosocial variables were examined. RESULTS: Five distinct trajectories of fatigue were identified: Stable Low (66%), with low levels of fatigue across assessments; Stable High (13%), with high fatigue across assessments; Decreasing (4%), with high fatigue at baseline that resolved over time; Increasing (9%), with low fatigue at baseline that increased over time; and Reactive (8%), with increased fatigue after treatment that resolved over time. Both psychological and treatment-related factors were found to be associated with fatigue trajectories, with psychological factors most strongly linked to high fatigue at the beginning of and over the course of treatment. CONCLUSIONS: There is considerable variability in the experience of fatigue among women with early-stage breast cancer. Although the majority of women report relatively low fatigue, those with a history of depression and elevated psychological distress may be at risk of more severe and persistent fatigue.