Abstract PS6-21: High expression of MicroRNA-223 indicates better prognosis in triple negative breast cancer

Abstract

Abstract Background: MicroRNAs (miRNAs) can influence many biological processes and also show promise as biomarkers for cancer. Few researches have focused on the expression of microRNA-223 (miR-223) and its precise role in breast cancer (BC). We aimed to examine the expression level of miR-223 and further explored the prognostic value in BC.Methods: Tissue microarray-based miRNA detection in situ hybridization with LNA probe was used to detect miR-223 expression in 450 BC tissue. Overall survival (OS) and disease-free survival (DFS) were compared between two groups using the Kaplan-Meier method and Cox regression model.Results: Better OS and DFS were observed in the high-miR-223 expression patients compared to those of low expression patients (P < 0.0001 and P = 0.017, respectively), especially in the triple-negative breast cancer (TNBC) subtype (P = 0.046and P < 0.001, respectively). Combined with the univariate and multivariate Cox regression analysis, TNM stage (p = 0.008), molecular subtype (p =0.049) and miR-223 (p < 0.001) were independently linked to OS and DFS. External validation was performed in METABRIC and TCGA database via online webtool and consistent with the data above.Conclusions: This study provided evidence that high-miR-223 expression at diagnosis was associated with better DFS and OS for BC, especially for the TNBC subtype. miR-223 is a valid and independent prognostic biomarker in BC. Table Univariate and multivariate survival analysis for disease-free survivalUnivariate MultivariateVariableHR95% CIP valueHR95% CIP valueAge0.594≤40 vs >601.3510.626-2.9140.44440-60 vs >600.9940.548-1.8030.984Menopausal statuspre vs post0.7370.487-1.1130.147DifferentiationII vs III0.7300.457-1.1640.186TNM stage0.0080.008II vs I1.4210.860-2.3460.1701.4850.887-2.4850.132III vs I2.7581.446-5.2590.0022.8581.469-5.5630.002Molecular subtype0.1940.049Luminal B vs Luminal A1.1060.580-2.1070.7600.8130.415-1.5930.546HER2+ vs Luminal A0.9860.497-1.9560.9670.7010.337-1.4580.342Triple-negative vs Luminal A1.6260.930-2.8430.0881.4930.849-2.6260.164MicroRNA-223low vs high3.9602.201-7.126<0.0013.7892.098-6.843<0.001Abbreviations: CI, confidence interval; HR, hazard ratio.The covariates in the Cox model were all categorical variables, and the adjusted p value and HR were derived from the model. Citation Format: Li Chen, Xiuzhi Zhu, Ling Yao, Zonghua Wang. High expression of MicroRNA-223 indicates better prognosis in triple negative breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS6-21.