Is osteocalcin marker for bone sarcomas in children and teenagers ?

45s A-091 THE EVALUATION OF ALKALINE PHOSPHATASE ISOENZYMES AND CORRELATION WITH BONE TUMORS,MAINLY RESPECTING THE BONE FRACTION OF ALKALINE PHOSPHATASE Andrea6 H.Beck,A.Clotten,R.Clotten (+) S.Strobel Univereitgtsklinik Freiburg Zentrum Radiologie D78 Freiburg 500 patients with increased alkaline phosphatase (AP) were investigated by a specific method of evaluation of AP - bone fraction. In case of increased AP bone fraction clinical diagnosis and radiological finding6 were compared.51 patient6 with bone tumours were divided according to alkaline phosphatase isoenzyme grouping.E)ven,whentotal AP wa6 not increased,e significant increase in AP bone fraction wa6 present with a corresponding decrease in the other fractions of AP. Alkaline phosphatasecan be divided into 5 isoenzymes using eleCtrOphOre6iS and a specific way of staining the samples. The isoenzymes may be divide& a6 follows: hepatic fraction,bone fraction,placental fraction in the last trimester of pregnancy,intestinal fraction and kidney fraction.Each fraction occupies a distinct place along the electrophoretic 6trip.Ben6itOmetry then provide6 a quantitative evaluation of the isoenzyme.The bone fraction is heat labile and can be diminished at 39,5 C.AP-1606nZYm6 examination is a valid screening method together with radiology and nuclear medicine to detect bone lesion6 easier even when visualisation is not Yet possible at the time of presentation. A-092 Value of L.A.S.A. in bone and soft tissue sarcomas in children. DELEPINE N, DELEPINE G,CORNILLE H, ALKALLAF S, DESBOIS JC, MUSSET M, MATHE G, Oncologic pediatric Unit H.Herold - PARIS SMST, H. Paul Brousse, VILLEJUIF In order to evaluate sensibility and specificity of the new tumor marker,LASA-lipid associated sialic acid-, in bone and soft tissues sarcomas in a pediatric population, we have compared 3 groups (g) a control g.:40 patients (p.)(21 without known pathology, 14 with benign osseous pain complete remission thology, 5 with inflammatory disease), a g. of 36 p. with malignancies (CR)(ll Ewing's sarcomas, 15 osteosarcomas, 10 soft tissue tumors) ; a 3e g. of evolutive maligancies (E.M.) (8 Ewing's sarcomas, 8 osteosarcomas, 6 soft tissue tumors) _______________~le2________-~~~________-__-_~~~~-~~~~_-__-__-_~~~~~~~~__-____~~_~~~~~~~~~____ Control g. 40 lO,Ol(l-21) 16,8 11,1- 27,5 19,37 CR g. 15,39(2-21) 36 18,72 12,5- 2499 9357 20,2 - 47,l E.M. 22 16,59(2-22) 32,43 38787 __--_-__-__-__--_~__-__-__-__-___--__-T__-__-_~--_-_~--_--_--__-__-__-__-__-__-__-__-_____~__ age and LASA level in Statistic evaluation shows : 1) significant correlations to 1Lbetween control g. (higher level in young population) 2) significant difference (>lO-'3) between mLASA in control g. and in RC, and mean LASA in E.M. 3) follow-up of LASA in our p. shows that, after complete surgery, LASA tends progressivly to normal values after the eighth month following surgery, but a new surgical act mays raise its temporary.Our preliminary results lead us to consider LASA a a good belong to evolutivity. Further study marker in bone sarcomas and soft tissue tumors, especially ra~cio tr assess the value of LASA to detect micrometastasis before clinical and radiological appea-

A-093 Is osteocalcin marker for bone sarcomas in children and teenagers ? N. DELEPINE, D.CHEVENNE, G.DELEPINE, O.RIGAL, M.LAFAY, D.PORQUET,H.CORNILLE,JC.DZSBOIS. H.HEROLD-PARIS-FRANCE Circulating osteocalcin (gla-protein) is essentially derived from a protein that is newly synthetized by and released from the osteoblastic cell population and not from resorption of existing bone matrix by osteoclasts. To evaluate bone metabolism in bone sarcomas, we studied two groups : 1) Evolutive bone sarcomas (osteosarcomas + Ewing's sarcomas) group (15~). 2) Control group (44~) same age (3-17 years) and sex. The patients were studied before any treatment (12) or just at the beginning of chemotherapy (3). Age n Mean OSTK Variance ~____________________-______-__-_-__-_________-__-__-_--_--__-__-__-__-__-__-__-__-__-_____ Control group sarcomas g.

3-17 (44) 3-17 (15)

1335 9,32

16 23,30

We found a significant difference (p(O,O5 t student test) between mean OSTK in control group and in bone sarcomas. There is a significant decreasing of mean OSTK in bone sarcomas. Further study must explain this behaviour, but individual values do not permit the use of OSTK as evolutivity's marker, the more because chemotherapy seems to decrease also OSTK.