Human Circulating Endorepellin LG3 Fragment and Breast Density: A Potential Combination with Screening Mammography in Women with Dense Breast.

Abstract

Abstract (Background) In vitro studies have reported that the endorepellin LG3 fragment (ERLG3F), which is matrix-derived endogenous anti-angiogenic factor, can be a circulating biomarker candidate for breast cancer. This study examined the plasma ERLG3F levels in breast cancer patients and normal healthy controls, and evaluated its potential roles as a screening biomarker for breast cancer (Methods) ERLG3F levels were determined by competitive ELISA in the plasmas from prospectively constructed independent cohorts (train and test set) from July 2006 to September 2007 for the Biomarker Discovery Project (funded by 21C Frontier Functional Proteomics Program of South Korea). The Breast Cancer Cohort (BC) (n=366) has plasmas drawn preoperatively; the Healthy Control Cohort (HC) (n=305), drawn when volunteers visited our Healthcare Center for medical check-up. Circulating ERLG3F, mammography, and the combining marker (CM) of both were evaluated for their performance of identifying breast cancer in the train set and verified again in the test set. (Results) Decreased ERLG3F levels were observed in the individual plasmas from BC compared to the HC. The decrease was significantly prominent in patients without axillary lymph node metastasis (negative vs. positive), young age (< 50 vs. ≥50 yr), and dense breast (mammographic density Gr 3 or 4 vs. 1 or 2). We used a cutoff level, which correspond to 2SD below the mean ERLG3F in total healthy controls. ERLG3F significantly improved the performance of mammography in distinguishing breast cancer cases from healthy controls, although it is less sensitive than mammography as a single marker. (Conclusion) We conclude that ERLG3F can be a useful diagnostic biomarker for breast cancer and its role can be even better when used for young women with dense breast for whom mammography is less helpful. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3026.