This research study will examine how often hypersensitivity, or allergic reactions, occur in patients receiving the chemotherapy medication oxaliplatin. Hypersensitivity reactions can vary from a transient skin rash and fever to more severe symptoms such as shortness of breath, chest tightness, and a more severe allergic reaction that can affect blood pressure called anaphylaxis. We will be examining how often hypersensitivity reactions occur and how severe the reactions are when they occur. We will also examine whether there are factors that place people at risk for developing hypersensitivity reactions to oxaliplatin. In an optional portion to this study, we will examine whether allergy skin testing can predict whether someone will develop a hypersensitivity reaction.