title: Pulsed-dye laser and retinoic acid delay progression of oral squamous cell carcinoma: a murine model.
abstract: OBJECTIVE
  This study examined the role of the pulsed-dye laser (PDL) at 585 nm coupled with retinoic acid at therapeutic (5.0 mg/kg) and nontherapeutic (0.5 mg/kg) doses to delay the progression of cancer with a two-hit approach. The existing vasculature is selectively targeted by the laser, whereas retinoic acid inhibits future angiogenesis.
  
  
  METHODS
  Randomized, prospective study in a murine model.
  
  
  METHODS
  Twenty-five athymic nude mice were inoculated with oral squamous cell cancers on six flank sites and randomly divided into five groups: 1) control subjects, 2) treatment with 0.5 mg/kg retinoic acid (RA 0.5), 3) treatment with 5.0 mg/kg retinoic acid (RA 5.0), 4) treatment with RA 0.5 + PDL, and 5) treatment with RA 5.0 + PDL. The PDL groups received irradiation after inoculation. The retinoic acid was administered daily. The tumors were counted and measured for 14 days.
  
  
  RESULTS
  The control group developed visible tumors in 50% of the inoculation sites at 3 days compared with 3 days (RA 0.5) and 4 days (RA 5.0) for the retinoic acid groups and 9 days (RA 0.5 + PDL) and 10 days (RA 5.0 + PDL) for the laser treatment groups. There was no tumor growth until day 7 in the RA 5.0 + PDL group. The tumor volume was statistically different between the treatment groups.
  
  
  CONCLUSIONS
  This study demonstrated the superiority of a single treatment with the PDL coupled with retinoic acid to delay the progression of cancer when compared with treatment with retinoic acid alone, thus introducing a novel strategy in cancer control.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Otolaryngology Research Center, Tufts-New England Medical Center, Boston, Massachusetts, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Shah
authors.forename: T A
authors.initials: TA
authors.lastname: Valdez
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: S M
authors.initials: SM
authors.lastname: Shapshay
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy / Q000628:therapy*; D003131:Combined Modality Therapy; D003627:Data Interpretation, Statistical; D004195:Disease Models, Animal; D053685:Laser Therapy; D017602:Lithotripsy, Laser; D051379:Mice; D008819:Mice, Nude; D009062:Mouth Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy / Q000628:therapy*; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy / Q000628:therapy; D011446:Prospective Studies; D011897:Random Allocation; D013997:Time Factors; D014212:Tretinoin / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D000970:Antineoplastic Agents; D014212:Tretinoin