Abstract

Serum levels of the tumor associated antigens CA125, CASA, OSA and MSA were determined preoperatively in a non-consecutive series of patients with: invasive epithelial ovarian cancer (OC, n = 87), ovarian tumors of low malignant potential (LMP, n = 9), benign adnexal masses (BAM, n = 48) and other peritoneal and pelvic malignancies (n = 48). In addition, serum levels of CASA, OSA, and MSA were determined in 3477 asymptomatic well women. Ninety-eight percent of the asymptomatic women had CASA levels < 6.0 U ml⁻¹, OSA levels < 5.5 U ml⁻¹ and MSA levels < 80.0 U ml⁻¹. Serum CA125 levels were> 35 U ml⁻¹ in 89% of OC, in 44% of LMP, and in 23% of BAM. Serum CASA levels were> 6.0 U ml⁻¹ in 58% of OC, in 0% of LMP, and in 0% of BAM. Serum OSA levels were> 5.5 U ml⁻¹ in 61% of OC in 0% of LMP and in 4% of BAM. Serum MSA levels were> 80.0 U ml⁻¹ in 56% of OC, in 11% of LMP, and in 10% of BAM. When cut-off levels were set to exclude all patients with BAM, the best discrimination from OC using a single assay was achieved using CASA (58%). However, a combination of CASA and CA125 gave positive levels in 69% of OC at levels which precluded BAM. All markers were also elevated in some colon cancers, cervical cancers, uterine cancers and other peritoneal malignancies. A combination of CA125 and CASA levels, obtained preoperatively may assist the general gynecologist in avoiding potentially difficult oncologic surgery.