A prospective cohort study of fatigue after adjuvant therapy for breast cancer: Association with hematologic, endocrine, and immune parameters.

9596 Background: Persisting fatigue states after cancer therapy remain a major survivorship issue, with up to 40% of individuals reported to experience disabling post cancer fatigue (PCF). An immunologic mechanism has been proposed.,Women with early stage breast cancer from six metropolitan teaching hospitals in Sydney, were enrolled post surgery. Clinical assessment and blood sampling was conducted at baseline (post surgery), end of adjuvant treatment, and then at 1, 3, 6, 9 and 12 months. Structured interviews and self-report questionnaires were used to record physical and psychological health and disability. Provisional PCF cases were assessed at 6 months to exclude alternative medical and psychiatric causes of fatigue. Nested case-control series were selected for hematologic (full blood count), endocrine (thyroid stimulating hormone, follicle stimulating hormone) and immune (cytokines, leukocyte subsets) testing.,Data from 218 enrolled women (median age 52 years) were evaluated. The PCF case rate was 24% (n=51) post surgery, 42% (90) at end-treatment, 19% (40) at 6 months and 14% (30) at 12 months. At each time point, approximately half of the PCF cases had co-morbid psychological disorder. Predictors of PCF both at end-treatment and at 6 months were fatigue post-surgery and mood disturbance post-surgery. There was no association between PCF and clinical, treatment, hematologic or endocrine parameters. Serum levels and in vitro production of cytokines (interleukin [IL]1, IL2, IL4, IL6, IL10, IL12, tumor necrosis factor and interferon gamma) did not differ between cases and controls. The proportion of activated leucocyte subsets were also comparable.,PCF is common, frequently associated with co- morbid mood disturbance, but only a small minority of cases experience substantial disability for more than 12 months. There is no evidence for immunologic disturbance as the underlying mechanism. This group requires further study to identify aetiology and appropriate targeted intervention(s). No significant financial relationships to disclose.