Serum levels of breast carcinoma antigen (CA 15.3) and urinary calcium excretion (UCa) were determined in 73 patients with breast cancer: 36 without bone metastases (stage I-IV) and 37 with bone metastases. The patients in the latter group were further investigated at 2,4 and 6 months from the start of treatment. Both markers showed significant elevations in the group with bone metastases (CA 15.3: P = 1.0×10–6, UCa: P = 8.6×10–9). The bone metastasis index (BMI), which represents the combination of the markers, had better diagnostic efficacy (90%) than CA 15.3 alone (84%) or UCa alone (82%). During treatment of bone metastasis, the longitudinal levels of the markers showed a highly significant association with the therapeutic response assessed by the UICC criteria. For identifying progression of disease, the diagnostic efficacy of CA 15.3, UCa and a combination of both, the so-called Biochemical Index of Response (BIR), was 65%, 70% and 79%, respectively, at two months and 89%, 84% and 92% at four months. Application of the tandem, CA 15.3 with UCa, was very useful for the detection of bone metastases and the prediction of response to therapy.
Effect of Late Night Calcium Supplements on Overnight Urinary Calcium Excretion in Premenopausal and Postmenopausal Women
