title: Effect of hyperbaric oxygen therapy on a murine squamous cell carcinoma model.
abstract: BACKGROUND
  Hyperbaric oxygen (HBO) therapy is sometimes used to assist in wound healing after major head and neck cancer surgery. However, there is concern that HBO treatments might enhance the growth of any residual microscopic disease. This was studied in a mouse model of squamous cell carcinoma (SCC).
  
  
  METHODS
  SCC-VII/SF tumor cells were cultured, and then injected (3 × 10(3) cells) into C3H/HeJ mice in 5 groups: subcutaneous (SQ) control (n = 13), SQ-immediate (n = 12), SQ-delayed (n = 13), tail vein control (n = 8), and tail vein immediate (n = 9). The 3 experimental groups were subjected to HBO therapy, 2.4 atm for 90 minutes, 5 days per week for 4 weeks, starting on postinjection day 3 ("immediate") or 10 ("delayed"). Tumors in the SQ mice were measured 3 times per week. Lung metastases in the tail vein mice were counted at necropsy.
  
  
  RESULTS
  At postimplantation day 28, when the immediate group completed its HBO therapy, the tumor volume in the SQ-immediate group was 49.1% higher than the control group, and the SQ-delayed group was 105.1% higher than controls (p < .05). Two weeks later, the SQ-immediate group and SQ-delayed group tumor volumes were still significantly higher than controls, but the difference was smaller (18.4% and 43.8%, respectively; p < .05 only for the delayed group). The tail vein groups had similar numbers of lung metastases, with a mean of 8.7 metastases in the control group and 9.0 metastases in the HBO group (not significant [NS]).
  
  
  CONCLUSIONS
  This study suggests that HBO therapy does accelerate the growth of microscopic foci of SCCs. This finding differs from some earlier studies and warrants further study.
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Randal C
authors.initials: RC
authors.lastname: Paniello
authors.forename: Patrick L
authors.initials: PL
authors.lastname: Fraley
authors.forename: Robert
authors.initials: R
authors.lastname: O'Bert
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000628:therapy*; D004195:Disease Models, Animal; D006258:Head and Neck Neoplasms / Q000473:pathology* / Q000628:therapy*; D006931:Hyperbaric Oxygenation / Q000009:adverse effects*; D051379:Mice; D008809:Mice, Inbred C3H; D000077195:Squamous Cell Carcinoma of Head and Neck; D047368:Tumor Burden
keywords: animal; hyperbaric; malignancy; squamous; therapy