7/30/2019 OVA2 Abstracts

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5573 General Poster Session (Board #48E), Mon, 8:00 AM-11:45 AM

A panel of biomarkers to improve specificity in presurgical assessment of adnexalmasses for risk of ovarian malignancy.

Zhen Zhang, Danni Li, Lori J. Sokoll, Xiaer Sun, Robert Bristow, Daniel W Chan; The Johns HopkinsUniversity, School of Medicine, Baltimore, MD; University of Minnesota Medical Center Fairview,

Minneapolis, MN; Johns Hopkins University School of Medicine, Baltimore, MD; University of California,Irvine, School of Medicine, Orange, CA

Background: OVA1 is a panel of biomarkers cleared by FDA currently in clinical use for pre-surgicalassessment of adnexal masses for risk of ovarian malignancy. To further improve the specificity of OVA1,we evaluated biomarkers using a designedset of clinical samples enriched with OVA1 false positive benignpatients and selected insulin-like growth factor binding protein 2 (IGFBP2), interleukin 6 (IL6), andfollicle-stimulating hormone (FSH) to be further evaluated along with the original five biomarkers of OVA1on a prospectively collected clinical sample set. The inclusion of FSH was to eliminate the need formenopause-specific cutoffs. Methods: Consecutive patients with a documented pelvic mass planned forsurgical intervention were prospectively enrolled at 27 sites. Exclusion criteria included a diagnosis ofmalignancy in the previous 5 years or initial enrollment by a gynecologic oncologist. At the time of analysis,384 subjects had all biomarker values. Among them 69 were ovarian cancer cases (13 LMPs, 27 stages 1/2,19 serous, 11 endometrioid , 5 mucinous, and 4 clear cell). Biomarkers were tested by ELISA and reportedas continuous values. Using a subset of the samples, the biomarkers were first selected for inclusion in afinal panel based on contributions in multivariate models estimated by bootstrap. The selected biomarkerswere further assessed for ability to improve specificity of risk stratification at a fixed sensitivity over thatof OVA1 using the full data set. This was done by cross-validation of multivariate models with 50/50 splitbetween training and testing. Results: The final panel of biomarkers consisted of CA125II, prealbumin,IGFBP2, IL6, and FSH. At a fixed sensitivity of 90%, the mean and median specificity of models using thenew panel in testing were 78.2% (95% CI: 76.7 79.8%), and 80.6%, respectively. The mean and medianabsolute improvements over that of OVA1 were 18.6% (95% CI: 16.4% 20.9%) and 20.3%, respectively.Conclusions: The new panel demonstrated the potential to significantly improve specificity over that of thefirst-generation OVA1 algorithm, while maintaining a high sensitivity in pre-surgical assessment of adnexalmasses for risk of malignancy.

GYNECOLOGIC CANCER

2013 American Society of Clinical Oncology. Visit abstract.asco.org and search by abstract for disclosure information.