The invention provides a method for determining the response of a mammalian tumor to a chemotherapeutic agent comprising detecting and quantifying the SPARC protein in a sample isolated from the human. The invention also provides a method for delivering a chemotherapeutic agent to a tumor in a human that expresses SPARC comprising administering a pharmaceutical composition comprising the chemotherapeutic agent coupled to a compound that binds SPARC protein. The invention further provides a composition comprising a chemotherapeutic agent coupled to a compound capable of binding SPARC protein and a pharmaceutically acceptable carrier.
