Cancer chemotherapy is not always effective.Difficulties in drug delivery to the tumor

drug toxicity to normal tissues

and drug stability in the body contribute to this problem.Biomedical polymers provide an al- ternative means for delivering chemotherapeutic agents.This article reviews the principle of chemotherapy using polymeric targeting drugs

polymer implants

injectable microspheres and polymeric chemoembolization

and summaries recent preclinical and clinical studies of these new technology for treating cancer.