title: Clinical significance of a serum CA15-3 surge and the usefulness of CA15-3 kinetics in monitoring chemotherapy response in patients with metastatic breast cancer.
abstract: One hundred and twenty-two patients in whom the CA 15-3 level showed either a decline (92 patients) or an acute surge followed by a decline (30 patients) after chemotherapy were included. The clinical characteristics between the two groups and the CA 15-3 kinetics using receiver operating characteristic curves were analyzed. Patients with a surge had a significantly higher risk of disease progression than patients without a surge (P = 0.004; odds ratio 2.62; 95% CI 1.45-4.72). The clinicopathologic characteristics were significantly different between the two groups with respect to the distribution of ER, PR, and HER2 status, relapse-free survival, and the severity and extent of the involved organs. For patients with a surge, a CA 15-3 slope threshold > -0.0038 was chosen with a sensitivity of 80.0% and a specificity of 80.4%. The area under the curve was 0.847 (95% CI 0.771-0.906; P = 0.0001). A significant correlation between PFS and CA 15-3 slope was shown with Cox-regression modeling (P = 0.036; hazard ratio [HR], 2.1; 95% CI 1.01-4.14).These kinetics may serve as a good predictive marker of treatment response and response duration.
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong Gangnam-gu, Seoul, 135-710, Korea.
authors.forename: Hyo Song
authors.initials: HS
authors.lastname: Kim
authors.forename: Yeon Hee
authors.initials: YH
authors.lastname: Park
authors.forename: Min Jae
authors.initials: MJ
authors.lastname: Park
authors.forename: Myung Hee
authors.initials: MH
authors.lastname: Chang
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Jun
authors.forename: Kyoung Ha
authors.initials: KH
authors.lastname: Kim
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Ahn
authors.forename: Won Ki
authors.initials: WK
authors.lastname: Kang
authors.forename: Keunchil
authors.initials: K
authors.lastname: Park
authors.forename: Young-Hyuck
authors.initials: YH
authors.lastname: Im