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.