(ChemotherapyAdvisor) – The multivariate index assay OVA1 demonstrated higher sensitivity and negative predictive value for presurgical detection of ovarian malignancy compared with clinical impression and CA125-II in an intended-use population of non-gynecologic oncology practices, a study reported in Gynecologic Oncology online November 21.

The multivariate index assay correctly identified 83.3% of malignancies missed by clinical impression and 70.8% of cases missed by CA125-II, noted Robert E. Bristow, MBA, MD, Director of Gynecologic Oncology Services at UC Irvine Healthcare, Irvine, CA, and colleagues.

The prospective, multi-institutional trial enrolled patients from 27 non-gynecologic oncology practices scheduled to undergo surgery for an adnexal mass. Preoperative CA125-II serum samples and physician assessment of risk of ovarian cancer were correlated with final surgical pathology.

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Of 494 patients evaluable for multivariate index assay, CA125-II, and clinical impression, 92 (18.6%) had a pelvic malignancy and primary ovarian cancer was diagnosed in 65 (13.2%); 43.1% had FIGO stage I disease.

For all ovarian malignancies, sensitivity of the multivariate index assay was 95.7% (95% CI 89.3–98.3) when combined with clinical impression. In early-stage disease, the multivariate index assay correctly predicted ovarian malignancy in 91.4% (95% CI 77.6–97.0) of cases vs 65.7% (95% CI 49.2–79.2) for CA125-II.

The multivariate index assay also predicted absence of an ovarian malignancy; negative predictive value was 98.1% (95% CI = 95.2–99.2).

“Both clinical impression and CA125-II were more accurate at identifying benign disease,” Dr. Bristow noted. “The multivariate index assay correctly predicted benign pathology in 204 patients (50.7%, 95% CI 45.9–55.6) when combined with clinical impression.”

Results of this and an earlier clinical study of the multivariate index assay showed that all combined modalities used in routine clinical assessment failed to predict cancers at a rate of more than 24%; however, when the assay was added, this rate dropped to approximately 4% in each study.

The study was funded by Vermillion Inc., Austin, TX.