ALKALINE-PHOSPHATASE ISOENZYMES IN DETECTION AND FOLLOW-UP OF BREAST-CANCER METASTASES

Alkaline phosphatase isoenzymes in bone and liver metastases of breast cancer were determined in 637 patients and during follow up in 116 pa tients, by agarose gel electrophoresis. The activity of total alkaline phosphatase, gamma glutamyl transferase, CEA and CA 15-3 was also det ermined. The sensitivity of bone alkaline phosphatase in bone metastas es detection was 39%, of electrophoresis (rotal alkaline phosphatase a nd specific isoenzymes) 48 % and of enzymes and tumor markers together 85% (n=62). For liver metastases gamma glutamyl transferase had the b est sensitivity (100%, n=19). Even though positive predictive value wa s only 6%, the sensitivity of liver alkaline phosphatase was 58% and o f electrophoresis 94%. The determination of alkaline phosphatase isoen zymes is a non-invasive, in-expensive, reproducable and rapid method t o detect progressive disease in breast cancer, especially in combinati on with the tumor markers CA 15-3 and CEA.