Plasma lipid-associated sialic acid and serum CA 125 as indicators of disease status with advanced ovarian cancer.

Levels of plasma lipid-associated sialic acid and serum cancer antigen 125 (CA 125) were measured in 49 consecutive patients with advanced ovarian cancer (International Federation of Gynecology and Obstetrics stages III or IV) and in 43 women with benign gynecologic diseases who served as controls. Levels were evaluated in 22 previously untreated patients before initial debulking surgery, in 11 with negative second-look operation, and in 16 with persistent or progressive disease confirmed by second-look operation or reexploration. Plasma lipid-associated sialic acid values had a sensitivity of 100% in previously untreated patients, a specificity of 73% in those with negative second-look, and a sensitivity of 87% in those with positive second-look, or persistent disease. CA 125 values were 77, 100, and 75%, respectively. By combining both markers, there were no false-negative results in previously untreated patients or false-positive results in those who were disease-free. Only one of 16 patients with persistent disease had false-negative results for both markers and progressive disease on reexploration. The predictive values of a positive assay with plasma lipid-associated sialic acid, CA 125, and both markers combined were 92.3, 100, and 100%, respectively. The predictive values of a negative assay were 80, 55, and 88.9%, respectively. The combined use of plasma lipid-associated sialic acid and CA 125 enhanced the individual reliabilities of these tests in patients with advanced ovarian carcinoma.