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Originally published as JCO Early Release 10.1200/JCO.2004.03.091 on September 20 2004 © 2004 American Society of Clinical Oncology. Preoperative Sensitivity and Specificity for Early-Stage Ovarian Cancer When Combining Cancer Antigen CA-125II, CA 15-3, CA 72-4, and Macrophage Colony-Stimulating Factor Using Mixtures of Multivariate Normal DistributionsFrom the Massachusetts General Hospital and Harvard Medical School, Boston, MA; The University of Texas M.D. Anderson Cancer Center, Houston, TX; Duke University Medical Center, Durham, NC; Johns Hopkins Medical Institutions, Baltimore, MD; Groningen University Hospital, Groningen, the Netherlands; and St Bartholomews Hospital, London, United Kingdom Address reprint requests to Steven J. Skates, PhD, Massachusetts General Hospital, 50 Stanford St, Suite 560, Boston, MA 02114, e-mail: sskates{at}partners.org PURPOSE: In CA-125based ovarian cancer screening trials, overall specificity and screening sensitivity of ultrasound after an elevated CA-125 exceeded 99.6% and 70%, respectively, thereby yielding a positive predictive value (PPV) exceeding 10%. However, sensitivity for early-stage disease was only 40%. This study aims to increase preoperative sensitivity for early-stage ovarian cancer while maintaining the annual referral rate to ultrasound at 2% by combining information across CA-125II, CA 15-3, CA 72-4, and macrophage colony-stimulating factor (M-CSF). For direct comparisons between marker panels, all sensitivity results correspond to a 98% fixed first-line specificity (referral rate 2%). PATIENTS AND METHODS: Logistic regression, classification tree, and mixture discriminant analysis (MDA) models were fit to a training data set of preoperative serum measurements (63 patients, 126 healthy controls) from one center. Estimates from the training set applied to an independent validation set (60 stage I to II patients, 98 healthy controls) from two other centers provided unbiased estimates of sensitivity. RESULTS: Preoperative sensitivities for early-stage disease of the optimal panels were 45% for CA-125II; 67% for CA-125II and CA 72-4; 70% for CA-125II, CA 72-4, and M-CSF; and 68% for all four markers (latter two results using MDA). CONCLUSION: Efficiently combining information on CA-125II, CA 72-4, and M-CSF significantly increased preoperative early-stage sensitivity from 45% with CA-125II alone to 70%, while maintaining 98% first-line specificity. Screening trials with these markers using MDA followed by referral to ultrasound may maintain previously high levels of specificity and PPV, while significantly increasing early-stage screening sensitivity. MDA is a useful, biologically justified method for combining biomarkers. Supported by a SPORE Grant in Ovarian Cancer 1P50 CA83639 from the National Cancer Institute, Department of Health and Human Services. A poster presentation of preliminary results from this study was given at the 38th Annual Meeting of the American Society of Clinical Oncology, Orlando, FL, May 18-21, 2002. Authors disclosures of potential conflicts of interest are found at the end of this article. This article has been cited by other articles:
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Copyright © 2004 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
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