Early tumor detection is a major issue in developing effective treatment strategies for breast cancer. In patients with advanced breast cancer, cancer cells spread from the breast and underarm lymph nodes to other areas of the body, resulting in poor prognosis and decreased patient survival. Current diagnostic methods poorly predict which patients will develop advanced cancer and as such, a high percentage of early-stage patients are currently given unnecessary or ineffective treatment. My research project aims to identify characteristics of early stage breast cancer that are associated with an increased risk of cancer progression. Breast cancer results from changes in the quality and/or quantity of certain gene products, within healthy breast tissue. These abnormalities can be a result of direct mutations or improper regulation of specific genes. MicroRNAs (miRNAs) are small molecules involved in gene regulation and have been shown to play a key role in initiation and progression of breast cancer. Mis-regulated expression of specific miRNAs contributes to cancer progression. In this study, I will compare differences in miRNA expression in advanced and early stage breast cancer samples, identifying specific miRNAs with altered expression during cancer progression. I will then characterize any DNA alterations and modifications occurring at the identified miRNA genes, aiming to identify new characteristics associated with an increased risk of advanced breast cancer. My initial studies will be performed in well-characterized cancer cell line models to identify target genes. These findings will then be expanded and applied to breast cancer patient samples. The ultimate aim of my research is to improve our understanding of mechanisms underlying cancer development, allowing us to develop novel diagnostic tests that can better predict patient outcome and lead to more effective treatment strategies.