Abstract
OBJECTIVES: To determine association between levels of peripheral blood cells and fatigue symptoms of men with nonmetastatic prostate cancer receiving external-beam radiation therapy (ebrt). ebrt is the second most common treatment modality used for treatment of nonmetastatic prostate cancer. Up to 71% of prostate cancer patients complain of fatigue during ebrt, which decreases their quality of life. METHODS: An exploratory and longitudinal study design. Men with prostate cancer who schedule to receive ebrt were enrolled under active protocol (NCT00852111). All study participants completed the Functional Assessment of Chronic Illness Therapy–Fatigue (facit-F) and had peripheral blood drawn at 3 time points: baseline (D0), midpoint (D21), and ebrt completion (D42). One-way repeated-measures analysis of variance (ANOVA) and multivariate linear regression were used for data analysis. RESULTS: The preliminary analysis included 34 prostate cancer patients. Results showed significant changes of fatigue scores, red blood cells (rbcs), hematocrit, hemoglobin, absolute basophil count, absolute lymphocyte count, and absolute reticulocyte count over time in patients during ebrt compared with baseline (p ≤ 0.05) At all 3 time points, deceasing hemoglobin (β = −2.5, p < 0.01) and increasing absolute reticulocyte count (β = 0.26, p < 0.01) and absolute basophil count (β = 233.0, p < 0.01) predict worsening fatigue. CONCLUSIONS: The study findings provide empirical evidence of the significant association in this population between worsening fatigue and changes in blood counts levels associated with anemia and inflammation. Interventions that address anemia and inflammation related to ebrt may reduce the fatigue symptoms experienced by these subjects.