Isoenzymes of alkaline and acid phosphatases as bones metastasis marker in breast cancer patients.

Bone alkaline phosphatase (B-ALP) and tartrate resistant acid phosphatase (TR-ACP) are markers of osteoblastic and osteoclastic activities respectively. During a period of up to two years, these isoenzymes have been assayed in the sera of 191 breast cancer patients; 80 had bone metastases (BM). In BM bearing patients, B-ALP activity was 261 IU/l and 63 IU/l for patients without BM; TR-ACP was respectively 6.6 and 3.3 IU/l. Specificity and sensitivity were calculated according to several criteria. These isoenzyme serum levels were well correlated with those of two breast cancer markers (CEA and CA15.3) and radiograph.