The role of tumour markers in predicting skeletal metastases in breast cancer patients with equivocal bone scintigraphy

Bone scintigraphy (BS) is commonly performed in the staging and postoperati ve monitoring of breast cancer. Nevertheless, due to low specificity it oft en demonstrates hot spots with equivocal interpretation, which may be misle ading in the management of these patients. The aim of this study was to ass ess the value of a serum tumour marker panel in selecting among the patient s with equivocal BS those with bone metastases. Between January 1986 and De cember 1995, 297 breast cancer patients were followed-up after mastectomy w ith serial determinations of a CEA-TPA-CA15.3 tumour marker panel, BS and l iver echography. The tumour marker panel was used to select patients with e quivocal BS for examination of suspicious bone areas by further imaging tec hniques. Up to December 1995, 158 (53%) patients showed an equivocal BS and 47 patients developed bone metastases. In the 158 patients with equivocal BS, prolonged clinical and imaging follow-up over 45 months (mean; range 12 -120) was used to ascertain the presence or absence of bone metastases. In these 158 patients the negative predictive value and positive predictive va lue of the tumour marker panel to predict bone metastases was 97% and 75% r espectively This study shows that in breast cancer patients the CEA-TPA-CA1 5.3 tumour marker panel has a high value in selecting those patients with b one metastases, or at high risk of developing clinically-evident bone metas tases, among the large number of subjects with equivocal BS.