title: Evolution of 5-fluorouracil-based chemoradiation in the management of rectal cancer.
abstract: 5-Fluorouracil (5-FU) is the most widely used agent for the management of colorectal cancer. Capecitabine is metabolized by three enzymatic actions, the last of which is mediated by thymidine phosphorylase, to produce 5-FU. Given the oral bioavailability of capecitabine as well as in-vitro and in-vivo findings showing higher expression of thymidine phosphorylase in tumor cells and xenografts compared with normal tissue, capecitabine is an evolving candidate in the management of colorectal cancer with antimetabolite-based therapy. An ideal radiosensitizing agent must balance oncological outcomes with adverse effects and feasibility of administration. This discussion addresses the evolving role of 5-FU in the management of rectal cancer in the neoadjuvant setting in combination with ionizing radiation.
authors.affiliation: Department of Medical Oncology, University of Texas, Southwestern Medical Center, Dallas, Texas 75390, USA. Prapti.Patel@phhs.org
authors.forename: Prapti A
authors.initials: PA
authors.lastname: Patel
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D000069287:Capecitabine; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000493:pharmacokinetics / Q000627:therapeutic use; D005472:Fluorouracil / Q000031:analogs & derivatives / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D020360:Neoadjuvant Therapy; D011838:Radiation-Sensitizing Agents / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000532:radiotherapy*
chemical_list: D000964:Antimetabolites, Antineoplastic; D011838:Radiation-Sensitizing Agents; D003841:Deoxycytidine; D000069287:Capecitabine; D005472:Fluorouracil