title: Salivary epidermal growth factor levels decrease in patients receiving radiation therapy to the head and neck.
abstract: OBJECTIVE
  The objective of this study was to assess changes in salivary epidermal growth factor (EGF) in patients receiving radiation therapy to the head and neck and to determine whether salivary EGF levels correlate with the severity of radiation-induced oral mucositis.
  
  
  METHODS
  Thirteen patients and 18 control subjects were enrolled in the study. Saliva was collected before, during (weekly), and after radiation therapy. Salivary total protein (TP) and EGF concentrations were measured and correlated with the severity of oral mucositis. The variability in normalized EGF (ngEGF/mgTP) values and mucositis scores were analyzed with analysis of covariance, and the adjusted correlation coefficient was calculated.
  
  
  RESULTS
  EGF levels decreased (P =.004), whereas TP levels increased over time (P =.039). A strong correlation was seen with decreasing normalized EGF values and more severe mucositis (P =. 0001).
  
  
  CONCLUSIONS
  A strong negative correlation between normalized EGF and mucositis severity suggests a possible role for EGF in the progression of radiation-induced mucosal breakdown.
authors.affiliation: University of Florida College of Dentistry, Department of Prosthodontics, Gainesville, Florida 32610, USA.
authors.forename: H B
authors.initials: HB
authors.lastname: Dumbrigue
authors.forename: P L
authors.initials: PL
authors.lastname: Sandow
authors.forename: K H
authors.initials: KH
authors.lastname: Nguyen
authors.forename: M G
authors.initials: MG
authors.lastname: Humphreys-Beher
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D004815:Epidermal Growth Factor / Q000032:analysis / Q000528:radiation effects*; D005260:Female; D006258:Head and Neck Neoplasms / Q000737:chemistry / Q000150:complications / Q000503:physiopathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000528:radiation effects; D012463:Saliva / Q000737:chemistry / Q000528:radiation effects*; D012471:Salivary Proteins and Peptides / Q000032:analysis / Q000528:radiation effects; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D013280:Stomatitis / Q000209:etiology / Q000503:physiopathology; D013997:Time Factors
chemical_list: D012471:Salivary Proteins and Peptides; D004815:Epidermal Growth Factor