Serum Bone Markers in Breast Cancer Patients During 5-Fluorouracil, Epirubicin and Cyclophosphamide (FEC) Therapy

Background: Chemotherapy with 5-fluorouracil, epirubicin and cyclophosphamide (FEC) is now indicated for adjuvant therapy of breast cancer. Its effects on serum bone markers and bone metabolism are unclear. Patients and Methods: The bone formation marker serum osteocalcin, the bone resorption marker serum carboxyterminal telopeptide of type I collagen (CTx), serum parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D) and calcium concentrations were assessed in nine premenopausal breast cancer patients with no distant metastases at baseline, before the fourth cycle and after the ninth cycle of FEC therapy. All patients became amenorrheic during chemotherapy. Results: Individual values of bone markers remained within the reference ranges. The mean concentrations increased slightly. The only significant changes from baseline were observed in serum osteocalcin; concentrations were 17.6±4.9 μg/l (mean±SD), 17.5±4.2 μg/l, 22.8±6.4 μg/l (p=0.003). Serum CTx concentrations were 998±605 pmol/l, 886±562 pmol/l and 1473±1102 pmol/l at baseline, before the 4th and after the 9th cycle (p=ns). Serum 25(OH)D concentrations were all very low (mean concentrations were 26.6±10.1 mmol/l, 29.9±6.5 mmol/l and 27.7±10.6 mmol/l) and remained stable as did mean serum PTH and calcium concentrations. Conclusion: The finding of slight increases of the bone markers suggests early bone loss in premenopausal women. The independent effects of estrogen deprivation on bone cannot be separated from the effects of FEC therapy on bone.