In the course of a study of serum phosphatase isoenzymes in cancer patients, a patient with bronchogenic carcinoma was discovered, whose serum contained an alkaline phosphatase which was indistinguishable from placental alkaline phosphatase. The same enzyme was demonstrated in high concentration in the neoplasm and its metastases. This single case demonstrates the possibility that elevated serum alkaline phosphatase in patients with metastatic cancer can be of neoplastic rather than of hepatic and osseous origin.
This work was aided by Grants P 106 and P 107 of the American Cancer Society, New York; Grant CA-07538 and Research Career Award K6-CA-18,453 (to W.H.F.) of the NIH, USPHS; and by Grant 07190 from the National Cancer Institute, USPHS.