Inflammation and dimensions of fatigue in women with early stage breast cancer: A longitudinal examination.

BackgroundFatigue is a common and long-lasting side effect of cancer. Although fatigue is a multidimensional symptom, biologic mechanisms of fatigue dimensions have not been identified.MethodsWomen recently diagnosed with early stage breast cancer (n = 192) completed assessments before and after adjuvant therapy and at 6-month, 12-month, and 18-month posttreatment follow-up visits. At each assessment, women completed the Multidimensional Fatigue Symptom Inventory and provided blood for protein markers of inflammation (tumor necrosis factor [TNF] alpha [TNF-α], soluble tumor necrosis factor receptor type II [sTNF-RII], interleukin 6 [IL-6], and C-reactive protein [CRP]). Mixed-effect linear models examined within-person and between-person associations between inflammatory markers and dimensions of fatigue.ResultsAnalyses demonstrated a positive within-person association between general fatigue and TNF-α (b = 1.67; p = .037), sTNF-RII (b = 2.77; p = .002), and IL-6 (b = 0.86; p = .010) when controlling for age, race, education, body mass index, and cancer stage. Similarly, there was a positive within-person association between physical fatigue and TNF-α (b = 1.58; p = .007), sTNF-RII (b = 2.38; p