Placental alkaline phosphatase and cancer antigen 125 in sera of patients with benign and malignant diseases.

Human placental alkaline phosphatase (hPLAP; EC 3.1.3.1), cancer antigen 125 (CA 125), and carcinoembryonic antigen (CEA) were determined in sera of patients with malignant and nonmalignant disorders. For CA 125 we used two different commercial assay systems, based on the same monoclonal antibody. hPLAP had the same sensitivity (20%) as CA 125 for detecting non-ovarian neoplasia, whereas that of CEA was 45%. For detecting ovarian cancer CA 125 (Cis kit) was slightly more sensitive (50%) than hPLAP (45%), much more than CEA (10%). hPLAP was increased in sera of 2% of patients with nonmalignant disorders, CA 125 in 23%, and CEA in 18%. hPLAP was increased in only one of 10 diabetic patients and two of 50 patients on chronic renal dialysis. CA 125 and CEA were respectively increased in 45% and 23% of all liver pathologies studied and in 12% and 17% of patients with renal insufficiency. The sensitivity of hPLAP for detecting ovarian cancer is slightly inferior to that of CA 125, but its specificity is much higher. We found the Abbott system for CA 125 to be more sensitive than the Cis system.