title: Combination chemoprevention with diclofenac, calcipotriol and difluoromethylornithine inhibits development of non-melanoma skin cancer in mice.
abstract: OBJECTIVE
  With increasing incidence of non-melanoma skin cancer (NMSC), focus on chemoprevention of this disease is growing. The aim of this study was to evaluate topical combination therapies as chemoprevention of UV radiation-induced tumors in a mouse model.
  
  
  METHODS
  A total of 160 SKH-1 mice were randomized to one placebo group and four chemoprevention groups (diclofenac plus difluoromethylornithine; diclofenac plus calcipotriol; difluoromethylornithine plus calcitriol; and diclofenac plus difluoromethylornithine plus calcipotriol). The mice received UVB radiation for 20 weeks followed by 17 weeks with topical application of chemoprevention. The number of mice with tumors, number of tumors per group and tumor area size were compared using a linear regression model.
  
  
  RESULTS
  Chemoprevention with diclonefac plus calcipotriol and diclonefac plus difluoromethylornithine had a significant inhibiting effect on the number of tumors per group and the area of tumors. Moreover, diclonefac plus difluoromethylornithine had a significant inhibiting effect on the number of mice with tumors.
  
  
  CONCLUSIONS
  Potentially, non-melanoma skin cancer in humans may be prevented with these agents with few adverse effects. Therefore, clinical studies are needed to determine their therapeutic/preventive effect and possible adverse effects.
authors.affiliation: Hindegade 5, 4. tv., 1303 København K, Denmark. HCPommergaard@gmail.com
authors.forename: Hans-Christian
authors.initials: HC
authors.lastname: Pommergaard
authors.forename: Jakob
authors.initials: J
authors.lastname: Burcharth
authors.forename: Jacob
authors.initials: J
authors.lastname: Rosenberg
authors.forename: Hans
authors.initials: H
authors.lastname: Raskov
mesh_terms: D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001835:Body Weight / Q000187:drug effects; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D018890:Chemoprevention; D004008:Diclofenac / Q000494:pharmacology / Q000627:therapeutic use*; D000518:Eflornithine / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D008545:Melanoma; D051379:Mice; D011230:Precancerous Conditions / Q000188:drug therapy / Q000473:pathology / Q000517:prevention & control*; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000517:prevention & control*; D016019:Survival Analysis
chemical_list: C055085:calcipotriene; D004008:Diclofenac; D002117:Calcitriol; D000518:Eflornithine
keywords: Chemoprevention; UV radiation-induced skin tumors; combination therapy; experimental model; non-melanoma skin cancer