Diagnostic value of high molecular weight alkaline phosphatase in detection of hepatic metastasis in patients with lung cancer.

High molecular weight alkaline phosphatase (HMW-ALP) was measured in the sera of 126 patients with lung cancer to determine its diagnostic value in the detection of hepatic metastasis. This isoenzyme was found in 21 of 24 patients with hepatic metastasis and in 27 of 102 patients without hepatic metastasis. When 10 U/L was used as a cut-off value, the sensitivity, specificity, and accuracy of this test were 71%, 89%, and 86%, respectively. From the standpoint of histologic type, this test was most useful in patients with small cell carcinoma. HMW-ALP was not detected in the sera of 15 controls. It is concluded that HMW-ALP is a useful marker for hepatic metastasis in patients with lung cancer.