Serum ostase in the follow-up of breast cancer patients

The present study was carried out on 152 patients divided into three groups: A) 73 underwent radical surgery for breast carcinoma without signs of metastases; B) 31 patients with radiologic and scintigraphic evidence of bone metastases originating from malignant mammary neoplasia (14 with only one and 17 with two or more localizations); C) 48 affected by simple mammary cysts. No patients had a previous history of primary or secondary bone pathologies or renal, hepatic or endocrine ones. Besides this, no patient took drugs influencing the metabolic turnover of the bony tissue in the three months preceding the study. After surgery all patients underwent standard clinical and laboratory follow-up, the latter including, every 3 months, the evaluation of serum CA 15.3, CA 27.29 MCA, and ostase. The ostase cut-off, obtained by the statistical elaboration of the serum values of the 48 patients with benign mammary cysts and the 73 disease free patients, was 17 microg./L. The mean concentration in the three groups and two subgroups was: 13.76 microg./L (patients without metastases), 31.84 (patients with metastases), 18.4 (limited bony metastases), 40.04 (diffused bony metastases) and 5,36 (mammary cists). The diagnostic sensitivity of ostase proved superior to that of CA 15.3 (84% vs 75%) except when considering the subgroup with limited metastases (71.4% vs 72.7%), while the specificity was similar (around 78%). CA 27.29 and MCA were not useful as markers of metastasis. In a longitudinal-perspective study it was possible periodically to test these markers in 13 patients, at fist, disease free and then with signs of bone progression evidence by skeletal scintigraphy. In 11 of these patients ostase and CA 15.3 showed increased values, on average 136 and 131 days respectively, before instrumental evidence of progression. None of the 13 patients, at the time of bone progression diagnosis, showed clinical, laboratory or instrumental signs of disease in other organs. The precocity of the serum increase of ostase could have a triple role: 1) accomplishment of a closer follow-up in patients at ''high risk'' of bone disease; 2) aid in the interpretation ''in a neoplastic sense'' of an ''uncertain image of hypercaptation''; 3) accomplishment of a supporting or specific oncology treatment at an earlier stage which may be of some advantage as regards quality of life.