Breast cancer is the most common type of cancer in women and their second leading cause of death among cancer. Fucosylated glycans are overeexpressed in breast cancer, such as sialyl-Lewis X/A (sLeX/A), and their expression is related to increased disease progression and metastasis. These glycans in tumor circulating cells mediate binding to vascular E-selectin, initiating tumor extravasation. However, their role(s) in breast carcinogenesis is still unknown.