The purpose of our study was to examine single and serial determinations of five biomarkers in asymptomatic women at risk for epithelial ovarian cancer to define median values and trends in a cancer-free cohort. Women were enrolled in the Gilda Radner Ovarian Cancer Detection program at Cedars-Sinai Medical Center, Los Angeles, California from July 1, 1991, to July 1, 1993. Biomarkers studied include CA-125, LASA, DM-70K, UGP, and HER-2. Biomarker values that were analyzed included those obtained on the first patient visit and in a subset of values evaluated at 6-month follow-ups. A total of 590 women were included in the study; 425 were premenopausal and 165 were postmenopausal. No one in this study group has developed ovarian cancer within a 12-month follow-up period. Postmenopausal women had significantly lower values for CA-125 (12 vs 19 U/ml, P = 0.0001) and higher values of LASA (16.6 vs 15.4 mg/dl, P = 0.0001), DM/70K (11 vs 0 U/ml, P < 0.001), UGP (3.3 vs 0.3 U/ml, P < 0.001), and HER-2 (12 vs 11 U/ml, P = 0.009) than premenopausal women. Less than 5% of the women had elevated tumor marker values on both screens except for CA-125, where 15% of women studied had two consecutive visits with elevated values (> 35 U/ml). Two women demonstrated an exponential rise in CA-125 between visits. Premenopausal women differ in median biomarker values compared to postmenopausal women. Elevations in single tumor markers, combinations of markers, and exponential increases of markers have all produced false-positive results for ovarian cancer within the 12-month follow-up period. Exponential increases produced the smallest false positive rate (n = 2), but further study and follow-up are needed to determine the efficacy of these tests in ovarian cancer screening.