Prospective study of fatigue and metabolic parameters in patients with early breast cancer (EBC) receiving concomitant radiotherapy and anthracycline-based adjuvant chemotherapy

852 Background: Fatigue affects the quality of life of cancer patients. Treatment and disease related factors contribute to the symptom. The metabolic factors involved have not been studied adequately in humans. We have initiated a clinical-metabolic study of the effect of adjuvant chemotherapy on fatigue, excluding confounding disease-related factors. The hypothesis was that chemotherapy affects mitochondrial energy production. Methods: Patients were treated with 6 cycles of adjuvant CEF, concurrent with locoregional radiotherapy. Consenting patients were prospectively followed with the FACT-F subscale; an standardized aerobic forearm exercise test with measurement of blood levels of lactate, pyruvate, pH, free carnitine and acylcarnitines, pO2, pCO2, urinary organic acids and arterial flow. All measurements were performed at baseline, after 3 and 6 cycles of chemotherapy, and 3 and 6 months of follow-up. The variables were determined at rest, during exercise and in the recovery phase. Results: Seventeen...