Ultrasound Beats CA-125 for Distinguishing Benign From Malignant Adnexal Masses

By Will Boggs, MD
NEW YORK (Reuters Health) Nov 19 - Pattern recognition on gray-scale and Doppler findings by an experienced ultrasound examiner is superior to serum CA-125 for discriminating between a benign and a malignant adnexal mass, according to a report in the November 21st issue of the Journal of the National Cancer Institute.
"The International Ovarian Tumor Analysis (IOTA) study not only demonstrated that in experienced hands ultrasound is significantly better than serum CA 125, but also that CA-125 does not give additional benefit in mathematical models developed to distinguish between benign and malignant masses," Dr. Dirk Timmerman explained to Reuters Health.
Dr. Timmerman from Katholieke Universiteit Leuven, Belgium and colleagues used information from the IOTA database to compare the diagnostic performance of pattern recognition by an experienced examiner with that of preoperative levels of serum CA-125 with regard to discriminating between benign and malignant adnexal masses and among subgroups of adnexal masses.
Pattern recognition correctly classified 93% of adnexal tumors as benign or malignant, the authors report, whereas a serum CA-125 cutoff value of 30 U/mL correctly classified 72% of the tumors as benign or malignant.
The superiority of pattern recognition over serum CA-125 persisted after stratifying for menopausal status and for each specific histological diagnosis, the investigators say.
Pattern recognition was also superior to serum CA-125 for discriminating between benign tumors and borderline tumors and between benign tumors and stage I primary invasive malignancies in both pre- and postmenopausal women.
"Currently we do not see a role for CA 125 for diagnosis, because of many false positive results in benign conditions (such as endometriosis, PID, and fibroids) and the high number of false negative results in borderline ovarian cancer and early stage invasive ovarian cancer," Dr. Timmerman said.
"There is still a lack of confidence in the use of ultrasonography despite numerous reports in the literature that transvaginal ultrasound can be used to classify most ovarian masses with a high degree of accuracy," Dr. Timmerman noted. "The accuracy, however, depends on the level of experience of the examiner, even though little variation in accuracy was found between experienced examiners."
J Natl Cancer Inst 2007;99:1706-1714.