Circulating tumor markers in the monitoring of gynecologic malignancies.

Plasma from 262 patients with gynecologic malignancies was assayed for levels of circulating tumor markers (CA 125, LSA [lipid associated sialic acid in plasma, LASA-P (Dianon Systems, Inc., Stratford, CT )], Ca 19-9, and carcinoembryonic antigen [CEA]) and correlated with the patients' clinical status. In the patients with ovarian cancer the sensitivities of LSA and CA 125 for patients with clinical evidence of disease were 71% and 76% respectively; the specificities for patients with no clinical evidence of disease were 90% and 86% respectively. Using both tumor markers, a sensitivity of 84% and specificity of 85% was obtained. Additionally, CA 125 was elevated in 59% of patients with clinically advanced or recurrent endometrial cancer, and LSA was elevated in 63% of patients with clinical evidence of cervical cancer. Neither CEA nor CA 19-9 levels correlated with clinical status in patients with ovarian or cervical cancer. The values of Ca 125 and LSA were examined in relation to the findings at second-look surgery in patients with ovarian cancer. Absence of elevated tumor markers does not obviate the need for second-look surgery; the false negative rate for CA 125 was 40% (6/15). However, the finding of two elevated plasma markers 1 month or more apart, in ovarian cancer patients who were clinically free of disease, was strongly suggestive of recurrent cancer; 13 of 14 such patients showed this association. This latter finding may help to identify a group of patients in whom early surgical intervention is indicated.