Elevated fibroblast growth factor 23 in women with malignant ovarian tumors

OBJECTIVE: To determine whether fibroblast growth factor 23 (FGF23) concentrations are altered in women with ovarian cancers in which FGF physiology is known to be abnormal. PATIENTS AND METHODS: Between May 2002 and September 2003 at the Mayo Clinic in Rochester, Minn, plasma or serum FGF23 concentrations were measured in 39 healthy women and in 14 with benign ovarian tumors, 14 with early-stage ovarian cancer, and 13 with advanced-stage ovarian cancer. Immunohistochemistry using anti-human FGF23 antibodies was performed on tissue from benign masses and advanced-stage tumors. RESULTS: Serum or plasma FGF23 concentrations were significantly higher in women with advanced-stage ovarian cancer compared with concentrations in women with early-stage ovarian cancer or benign disease or in healthy women. A significant positive correlation was seen between serum iFGF23 and cFGF23 concentrations and stage of disease. Serum iFGF23 and cFGF23 concentrations were positively correlated with serum phosphorus among women with ovarian cancer. No patients with elevated iFGF23 or cFGF23 concentrations had hypophosphatemia. Immunohistochemistry detected FGF23 tissue staining in malignant ovarian cancer cells. CONCLUSION: Serum or plasma FGF23 concentrations are elevated in patients with advanced-stage epithelial ovarian cancer without reductions in serum phosphate concentrations. The presence of elevated FGF23 concentrations in patients with an ovarian mass should suggest advanced-stage disease.