The present invention provides methods for the preselection of a subject for therapeutic treatment with an agent based on modulated levels of hypoxia in cancerous cells in the subject. In one embodiment, the invention provides methods for the preselection of a subject for therapeutic treatment with an agent based on modulated levels of lactate dehydrogenase (LDH) in a cell, e.g., a cancerous cell. The invention also provides methods for treating cancer in a subject by administering an effective amount of an agent to the subject, wherein the subject has been selected based on a modulated level of hypoxia. The invention further provides kits to practice the methods of the invention.
