title: Predictors of weight loss during radiotherapy in patients with stage I or II head and neck cancer.
abstract: BACKGROUND
  The purpose of the study was to identify predictors of weight loss during radiotherapy (RT) in patients with stage I or II head and neck (HN) cancer.
  
  
  METHODS
  This study was conducted as part of a phase 3 chemoprevention trial. A total of 540 patients were randomized. The patients were weighed before and after RT. Their baseline characteristics, including lifestyle habits, diet, and quality of life, were assessed as potential predictors. Predictors were identified using multiple linear regressions. The reliability of the model was assessed by bootstrap resampling. A receiver operating characteristics curve was generated to estimate the model's accuracy in predicting critical weight loss (>or=5%).
  
  
  RESULTS
  The mean weight loss was 2.2 kg (standard deviation, 3.4). Five factors were associated with a greater weight loss: all HN cancer sites other than the glottic larynx (P<.001), higher pre-RT body weight (P<.001), stage II disease (P = .002), dysphagia and/or odynophagia before RT (P = .001), and a lower Karnofsky performance score (P = .028). There was no association with pre-RT lifestyle habits, diet, or quality of life. The bootstrapping method confirmed the reliability of this predictive model. The area under the curve was 71.3% (95% confidence interval, 65.8-76.9), which represents an acceptable ability of the model to predict critical weight loss.
  
  
  CONCLUSIONS
  These results could be useful to clinicians for screening patients with early stage HN cancer treated by RT who require special nutritional attention.
authors.affiliation: Clinical Epidemiology Unit, Laval University Cancer Research Center, CHUQ-Hôtel Dieu de Québec, Quebec City, Quebec, Canada. alice.nourissat@wanadoo.fr
authors.forename: Alice
authors.initials: A
authors.lastname: Nourissat
authors.forename: Isabelle
authors.initials: I
authors.lastname: Bairati
authors.forename: Elodie
authors.initials: E
authors.lastname: Samson
authors.forename: André
authors.initials: A
authors.lastname: Fortin
authors.forename: Michel
authors.initials: M
authors.lastname: Gélinas
authors.forename: Abdenour
authors.initials: A
authors.lastname: Nabid
authors.forename: François
authors.initials: F
authors.lastname: Brochet
authors.forename: Bernard
authors.initials: B
authors.lastname: Têtu
authors.forename: François
authors.initials: F
authors.lastname: Meyer
mesh_terms: D001835:Body Weight; D015897:Comorbidity; D003680:Deglutition Disorders / Q000150:complications; D004032:Diet; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D011379:Prognosis; D011788:Quality of Life; D011878:Radiotherapy / Q000009:adverse effects*; D015203:Reproducibility of Results; D012737:Sex Factors; D015431:Weight Loss