Measurement of Ionized Calcium as Supplementary Marker of Bone Metastasis in Breast Cancer
The serum concentrations of ionized calcium (iCa), corrected automatically for serum pH, were measured in 67 cases with breast cancer (16 positive cases and 51 negative cases for bone metastasis). The serum concentration of iCa in the cases of positive bone metastasis was significantly higher than that in the negative cases (p<0.005). As osteoclastic bone metastasis occurred frequently in breast cancer, the measurements of serum concentrations of iCa might be of help as a supplementary marker of the diagnosis of bone metastasis.