title: Candidate mechanisms for capecitabine-related hand-foot syndrome.
abstract: OBJECTIVE
  The oral fluoropyrimidine prodrug capecitabine is widely used in oncology. Capecitabine was designed to generate 5FU via the thymidine phosphorylase (TP) enzyme, preferentially expressed in tumoral tissues. Hand-foot syndrome (HFS) is a limiting toxicity of capecitabine. A pilot study on healthy volunteers was conducted in order to test the hypothesis that the occurrence of HFS could be related to tissue-specific expression of drug-metabolizing enzymes in the skin of the palm and sole. To this end, the expression of TP (activating pathway), dihydropyrimidine dehydrogenase (DPD, catabolic pathway) and cell proliferation (Ki67) were measured in the skin of the palm (target tissue for HFS) and of the lower back (control area).
  
  
  METHODS
  Two paired 4-mm diameter punch biopsy specimens (palm and back) were taken in 12 healthy volunteers. Immunohistochemical analyses were performed on frozen tissues.
  
  
  RESULTS
  Proliferation rate (Ki67 staining) was significantly higher in epidermal basal cells of the palm compared with the back (P = 0.008). Also, TP and DPD expression were significantly greater in the palm relative to the back (P = 0.039 and 0.012, respectively). TP and Ki67 expression were positively and significantly correlated in the palm.
  
  
  CONCLUSIONS
  The high proliferation rate of epidermal basal cells in the palm could make them more sensitive to the local action of cytotoxic drugs. TP-facilitated local production of 5FU in the palm during capecitabine treatment could explain the occurrence of HFS. This observation may support future strategies to limit the occurrence of HFS during capecitabine therapy.
authors.affiliation: INSERM ERI-21, Faculté de Médecine, CHU de Nice, Nice, France. gerard.milano@nice.fnclcc.fr
authors.forename: Gérard
authors.initials: G
authors.lastname: Milano
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Etienne-Grimaldi
authors.forename: Mireille
authors.initials: M
authors.lastname: Mari
authors.forename: Sandra
authors.initials: S
authors.lastname: Lassalle
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Formento
authors.forename: Mireille
authors.initials: M
authors.lastname: Francoual
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Lacour
authors.forename: Paul
authors.initials: P
authors.lastname: Hofman
mesh_terms: D000328:Adult; D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects; D001706:Biopsy; D000069287:Capecitabine; D049109:Cell Proliferation / Q000187:drug effects; D003841:Deoxycytidine / Q000009:adverse effects / Q000031:analogs & derivatives*; D005260:Female; D005472:Fluorouracil / Q000009:adverse effects / Q000031:analogs & derivatives*; D005533:Foot Dermatoses / Q000139:chemically induced* / Q000473:pathology; D006229:Hand Dermatoses / Q000139:chemically induced* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012871:Skin Diseases / Q000139:chemically induced* / Q000473:pathology
chemical_list: D000964:Antimetabolites, Antineoplastic; D003841:Deoxycytidine; D000069287:Capecitabine; D005472:Fluorouracil