Early Detection Research Network

Strategies for improving the specificity of screening for ovarian cancer with tumor-associated antigens CA 125, CA 15-3, and TAG 72.3.

To assess different strategies for improving the specificity of screening for ovarian cancer with tumor-associated antigens, including concomitant measurement of multiple tumor markers and serial measurement of CA 125.

A combination of CA 125, CA 15-3, and TAG 72.3 was evaluated in serum samples from 217 of 1010 apparently healthy postmenopausal women who had participated in a study of screening for ovarian cancer and who had a serum CA 125 level of 20 U/mL or greater. In addition, serial serum CA 125 levels were determined in 30 women with an initially elevated CA 125 level (30 U/mL or more) and 30 women with a CA 125 level less than 30 U/mL.

The specificity of CA 125 at upper limits of 30 and 50 U/mL was increased from 97.0 and 99.5%, respectively, to 98.9 and 99.9% when a positive test was defined as an elevated serum CA 125 level in combination with either a CA 15-3 greater than 30 U/mL or a TAG 72.3 greater than 10 U/mL. Definition of a positive result as a serum CA 125 level greater than 50 U/mL at the initial test and greater than 30 U/mL at 3-month follow-up achieved a specificity of 99.6%.

Levels of specificity suitable for screening asymptomatic postmenopausal women can be achieved using tumor-associated antigens measured serially or in combination. Further studies are required to determine the sensitivity of these strategies for preclinical ovarian cancer.

Bast RC, Jacobs IJ, Oram DH

1495694

Obstet Gynecol, 1992, 80 (3 Pt 1)