RESUMO
BACKGROUND: Fatigue remains a prevalent, persistent, and debilitating side effect of chemotherapy for stage I and II breast cancer patients. Severity of fatigue varies among patients. Evidence suggests that proinflammatory cytokines contribute to the development of fatigue. OBJECTIVE: The aim of this study is to investigate predictors of fatigue and cytokine levels in women undergoing chemotherapy for stage I or II breast cancer. METHODS: Piper Fatigue Scales and blood samples for interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels were collected at baseline and days 7, 14, and 21 for each chemotherapy cycle. Descriptive statistics, general linear mixed models, and graphic analysis were used to analyze the data. RESULTS: The predominantly white convenience sample was composed of 11 women with stage I or II breast cancer who were 37 to 72 years old (mean, 52 years). Predictors of fatigue were type of chemotherapy drugs, time, and IL-6 levels. A predictor of IL-6 and TNF-α levels was whether chemotherapy was administered at the visit. Type of chemotherapy significantly predicted TNF-α levels. Fatigue patterns were characterized by chaotic pattern of peaks and troughs unique to each woman. CONCLUSIONS: Women with stage I and II breast cancer experienced variability in the severity of fatigue and levels of IL-6 and TNF-α throughout their treatment trajectories. The presence and role of genetic variants related to cancer-related fatigue may explain the individual variation and warrant further research. IMPLICATIONS FOR PRACTICE: These findings highlight the importance of symptom assessments including fatigue at each clinic visit and individualized interventions throughout the cancer trajectory.
