title: High perioperative level of oxidative stress as a prognostic tool for identifying patients with a high risk of recurrence of head and neck squamous cell carcinoma.
abstract: BACKGROUND
  The aim of the study was to investigate the relationships among (a) glutathione peroxidase (GPx) and malondialdehyde (MDA); (b) oncological characteristics (i.e., TNM classification, tumor grade), and; (c) prognosis of head and neck squamous cell carcinoma.
  
  
  METHODS
  In a prospective cohort study, we followed 88 patients for 67.4 months (median 40.3) after surgery for head and neck squamous cell carcinoma. Activity of GPx was determined by ELISA and plasma MDA concentration by liquid chromatography.
  
  
  RESULTS
  Lower GPx activity was observed in the T3/4 patients than in the T1/2 group. Tumor grade was significantly correlated with both GPx (P = 0.001) and MDA (P = 0.05, both Spearman). The perioperative level of MDA was higher in patients who later recurred during the follow-up period (n = 15) than in the complete remission group (P = 0.01, Mann-Whitney). Median disease-free interval and overall survival in the group with MDA > median were 29.5 and 32.0 months, respectively, and 38.4 and 40.3 months in the patient group with MDA ≤ median (P = 0.10 and P = 0.08, respectively; Kaplan-Meier). Patients with MDA levels higher than the median had a more than twofold greater risk of recurrence than patients with MDA levels smaller than the median (31.3 vs. 15.2%, P = 0.06, logrank).
  
  
  CONCLUSIONS
  Our results suggest that an increased MDA level at the time of initial surgery is found in patients with a high risk of recurrence, which suggests that each patient can be categorized according to risk of recurrence based on their MDA level at the time of initial surgery.
authors.affiliation: Department of Otorhinolaryngology and Head and Neck Surgery, St Anne's Faculty Hospital, Pekařská 53, 656 91 Brno, Czech Republic.
authors.forename: Richard
authors.initials: R
authors.lastname: Salzman
authors.forename: Lukáš
authors.initials: L
authors.lastname: Pácal
authors.forename: Kateřina
authors.initials: K
authors.lastname: Kaňková
authors.forename: Josef
authors.initials: J
authors.lastname: Tomandl
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Horáková
authors.forename: Eva
authors.initials: E
authors.lastname: Tóthová
authors.forename: Rom
authors.initials: R
authors.lastname: Kostřica
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005979:Glutathione Peroxidase / Q000378:metabolism; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000378:metabolism*; D009367:Neoplasm Staging; D018384:Oxidative Stress; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D015996:Survival Rate
chemical_list: D008315:Malondialdehyde; D005979:Glutathione Peroxidase