SERUM OSTASE IN THE FOLLOW-UP OF BREAST-CANCER PATIENTS

The present study was carried out on 152 patients divided into three g roups: A) 73 underwent radical surgery for breast carcinoma without si gns of metastases; B) 31 patients with radiologic and scintigraphic ev idence of bone metastases originating from malignant mammary neoplasia (14 with only one and 17 with two or more localizations); C) 48 affec ted by simple mammary cysts. No patients had a previous history of pri mary or secondary bone pathologies or renal, hepatic or endocrine ones . Besides this, no patient took drugs influencing the metabolic turnov er of the bony tissue in the three months preceding the study. After s urgery all patients underwent standard clinical and laboratory follow- up, the latter including, every 3 months, the evaluation of serum CA 1 5.3, CA 27.29 MCA, and ostase. The ostase cut-off, obtained by the sta tistical elaboration of the serum values of the 48 patients with benig n mammary cysts and the 73 disease free patients, was 17 microg./L. Th e mean concentration in the three groups and two subgroups was: 13.76 microg./L (patients without metastases), 31.84 (patients with metastas es), 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 s ubgroup with limited metastases (71.4% vs 72.7%), while the specificit y was similar (around 78%). CA 27.29 and MCA were not useful as marker s of metastasis. In a longitudinal-perspective study it was possible p eriodically to test these markers in 13 patients, at fist, disease fre e and then with signs of bone progression evidence by skeletal scintig raphy. In 11 of these patients ostase and CA 15.3 showed increased val ues, on average 136 and 131 days respectively, before instrumental evi dence of progression. None of the 13 patients, at the time of bone pro gression diagnosis, showed clinical, laboratory or instrumental signs of disease in other organs. The precocity of the serum increase of ost ase could have a triple role: 1) accomplishment of a closer follow-up in patients at ''high risk'' of bone disease; 2) aid in the interpreta tion ''in a neoplastic sense'' of an ''uncertain image of hypercaptati on''; 3) accomplishment of a supporting or specific oncology treatment at an earlier stage which may be of some advantage as regards quality of life.