Saliva and serum CA 125 assays for detecting malignant ovarian tumors

The aim of this study was to determine whether CA 125 was present in saliva and, if it was present, to compare saliva and serum levels in patients with pelvic masses in order to determine whether saliva assays would be useful in identifying patients with ovarian malignancies. Saliva and serum CA 125 levels were assayed in specimens obtained from 55 normal healthy women, 92 patients with benign pelvic masses, and 41 patients with malignant pelvic tumors. We defined a serum CA 125 value greater than 65 U/mL and a saliva CA 125 value greater than 3000 U/mL as the positivity criteria. No serum or saliva assay was positive in the 55 normal women. The sensitivities of the saliva and serum CA 125 assays in 16 patients with epithelial ovarian cancer were 81.3 and 93.8%, respectively. A linear correlation was observed between serum and saliva CA 125 levels. The false-positive rates of serum CA 125 in patients with endometriomas and pelvic tuberculosis were 72.7 and 80%, respectively, but the false-positive rates for saliva CA 125 assays were only 13.6 and 10%, respectively. Therefore, the saliva CA 125 assay had a better diagnostic value than the serum CA 125 assay. In addition, collection of saliva is simple, noninvasive, and inexpensive, and samples could be obtained easily and repeatedly. For these reasons, assays of saliva CA 125 levels may be a new way of screening for malignant ovarian tumors.