title: Effect of low-level laser therapy on chemoradiotherapy-induced oral mucositis and salivary inflammatory mediators in head and neck cancer patients.
abstract: OBJECTIVE
  Oral mucositis (OM) is considered a painful and debilitating side effect in patients receiving head and neck cancer treatment. Low-level laser therapy (LLLT) proved to be effective to prevent and treat chemoradiotherapy-induced OM. The aim of this study was to evaluate the effect of LLLT in the severity of OM in patients with head and neck cancer and on the release of salivary inflammatory mediators. Clinical (score of OM severity) and biochemical parameters (concentration of inflammatory mediators, growth factors, and enzymes in saliva) were used.
  
  
  METHODS
  Thirty patients were randomized into two groups: control and laser. LLLT was performed three times a week in the laser group, while control group received sham irradiation. OM severity was assessed according to the World Health Organization (WHO) and National Cancer Institute (NCI) scales. Pro-inflammatory and anti-inflammatory cytokines (TNF-α, IL-6, IL-1β, IL-10, TGF-β), growth factors (EGF, FGF, VEGF), and metalloproteinases (MMP2/TIMP2, MMP9/TIMP2) concentrations were assessed using ELISA test. Saliva samples were collected on admission, and at the 7th, 21st, and 35th sessions of radiotherapy.
  
  
  RESULTS
  The laser group showed a reduction in the severity of OM, which coursed with significantly diminished salivary concentration of EGF and VEGF in the 7th radiotherapy session and of IL-6 and FGF in the 35th. There was a trend for reduced levels of IL-1β, TNF-α, IL-10, TGF-β, MMP2/TIMP2, MMP9/TIMP2 in the laser group compared to the control, however, no statistically significant differences were found.
  
  
  CONCLUSIONS
  These findings demonstrated that LLLT was effective in reducing the severity of chemoradiotherapy-induced OM and was associated with the reduction of inflammation and repair.
authors.affiliation: Department of Oral Medicine (Oral Pathology), Dental School, Federal University of Goiás, Goiânia, Goiás, 74605-220, Brazil.
authors.forename: Angélica F
authors.initials: AF
authors.lastname: Oton-Leite
authors.forename: Geisa Badauy L
authors.initials: GB
authors.lastname: Silva
authors.forename: Marília O
authors.initials: MO
authors.lastname: Morais
authors.forename: Tarcília A
authors.initials: TA
authors.lastname: Silva
authors.forename: Cláudio R
authors.initials: CR
authors.lastname: Leles
authors.forename: Marize Campos
authors.initials: MC
authors.lastname: Valadares
authors.forename: Juliana Castro D
authors.initials: JC
authors.lastname: Pinezi
authors.forename: Aline C
authors.initials: AC
authors.lastname: Batista
authors.forename: Elismauro F
authors.initials: EF
authors.lastname: Mendonça
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000532:radiotherapy; D059248:Chemoradiotherapy / Q000009:adverse effects*; D016207:Cytokines / Q000378:metabolism; D004311:Double-Blind Method; D004815:Epidermal Growth Factor / Q000378:metabolism; D005260:Female; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000532:radiotherapy; D006801:Humans; D028022:Low-Level Light Therapy; D008297:Male; D045726:Metalloproteases / Q000378:metabolism; D008875:Middle Aged; D012463:Saliva / Q000378:metabolism*; D012720:Severity of Illness Index; D013280:Stomatitis / Q000532:radiotherapy*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D016207:Cytokines; D042461:Vascular Endothelial Growth Factor A; D004815:Epidermal Growth Factor; D045726:Metalloproteases
keywords: cytokines; growth factors; head and neck cancer; laser therapy; matrix metalloproteinases