Clinicopathological and prognostic significance of SDC1 overexpression in breast cancer

Background Breast cancer is the leading cause of cancer death among global women, and its early diagnosis and treatment are very urgent. Syndecan-1 (SDC1) is a heparin sulfate proteoglycan, which has been linked with the prognosis and treatment response in a various tumor type. To investigate whether SDC1 can serve as a prognostic indictor in breast cancer, bioinformatic analyses were performed in the present study. Methods SDC1 expression was assessed using Oncomine analysis. Kaplan-Meier Plotter and bc-GenExMiner were performed to identify the prognostic roles of SDC1 in breast cancer. COSMIC analysis and cBioPortal database were performed to analysis the mutations of SDC1. The heat map and methylation status of SDC1 were identified by performing the UCSC. Results We found that SDC1 was more frequently overexpressed in breast cancer than their normal tissues and its expression might be negatively related with some CpG sites. Meanwhile, pooled data suggested that SDC1 mRNA expression is associated worse prognosis of breast cancer. Following data mining in multiple big databases confirmed a positive correlation between SDC1 mRNA expression and PLAU mRNA expression in breast cancer tissues. In addition, high SDC1 expression is associated with increased risked of age, nodal, HER2 and higher SBR grade status. Conclusion Our findings suggest that overexpressed SDC1 was identified in breast cancer than in matched normal tissues and is associated with methylation status of SDC1 promoter. Additionally, SDC1 is positively associated with PLAU and might act as a potential prognostic indicator for breast cancer.