Leukocyte alkaline phosphatase and serum alkaline phosphatase in patients with metastatic breast and colon cancer.

Peripheral blood leukocyte alkaline phosphatase (LAP) scores and serum alkaline phosphatase (SAP) levels in 70 patients with metastatic breast and colorectal cancer (metastases to the liver, lung, bone and abdomen) and in 18 healthy controls were measured. The mean LAP score in the metastatic cancer patients was significantly higher than in the control group (244 vs. 61) and there was no overlap between the 95% confidence level intervals of the two groups. The mean (SAP) level in the metastatic patients was also higher than in the controls (249 u/l vs. 162 u/l) but the 95% confidence level interval of the controls was inside the 95% interval of the metastatic patients meaning that considerable percentage of the metastatic patients will have a SAP level within the normal range. We conclude that of the two markers, the LAP is the better one for detection of metastatic tumors.