I J Jacobs1, D H Oram, R C Bast. 1. Department of Obstetrics and Gynecology, University of Cambridge, Rosie Maternity Hospital, United Kingdom.
Abstract
OBJECTIVE: 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. METHODS: 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. RESULTS: 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%. CONCLUSION: 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.
OBJECTIVE: 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. METHODS: 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. RESULTS: 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%. CONCLUSION: 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.