Cancer is a disease characterized by unregulated cell growth. Complex sugars are involved in the conversion of normal cells into cancerous cells, regulating tumor growth, and playing a role in tumor invasion and metastasis. As normal cells change into cancerous cells, the sugar coats on their cell surfaces also change as part of tumor progression. Detection of these changes potentially provides a new, sensitive means to detect cancer. In addition, since sugars play a role in tumor growth and metastasis, the introduction of sugar structures that can prevent these processes provides a potential avenue for the development of new therapeutics. Through our research, we have shown that selected sugars selectively inhibit proliferation of cancer cells and increase cancerous cell apoptosis, or cell death. In this way, they may be capable of both inhibiting tumor growth and preventing metastasis. Finally, better insight into the role that sugars play in modulating protein pathways can aid in our understanding of cancer mechanisms and the discovery of new small molecule and antibody drugs.