title: Nutritional deterioration in cancer: the role of disease and diet.
abstract: OBJECTIVE
  Under-nutrition is a major source of morbidity and mortality in cancer patients. This prospective, cross-sectional study aimed to evaluate the relative contributions of cancer staging, duration and diet on patients' nutritional deterioration.
  
  
  METHODS
  We included 205 consecutive patients (133 men and 72 women) with head and neck, gastro-oesophageal, colon and rectum cancer, age 53 +/- 12 (33-86) years, referred for radiotherapy (primary, adjunctive to surgery, combined with chemotherapy or with palliative intent). We registered clinical variables, nutritional status (percentage of weight loss, Patient-Generated Subjective Global Assessment and body mass index), nutritional requirements, usual diet intake (diet history) and current intake (24-h recall).
  
  
  RESULTS
  In stage III and IV, we observed a significant decrease of usual and current energy and protein intake (P=0.002), which were not observed in stage I and II. Reduction in nutritional intake was influenced by disease duration (P=0.04), but when the latter was evaluated in a multivariate analysis, current dietary intake was associated only with staging (P=0.004), thus disclosing a distinct pattern of nutritional intake between stages and diagnosis. Using a general linear model, advanced staging showed the most significant association with nutritional depletion (P=0.0001). We also found significant associations for tumour location (P=0.001), disease duration (P=0.002), nutritional intake (P=0.003) and previous surgery or chemotherapy (P=0.02). Percentage weight loss showed a consistently superior performance with regard to clinical variables and ability to detect mild to extreme nutritional changes. Patient-Generated Subjective Global Assessment had a very high sensitivity and specificity, and a strong capacity for detecting patients at nutritional risk compared with body mass index.
  
  
  CONCLUSIONS
  Nutritional depletion is multifactorial, dependent mainly on the tumour burden of the host. Percentage weight loss is a sensitive and specific tool that can screen and identify malnutrition effectively. Its joint use with Patient-Generated Subjective Global Assessment, which establishes boundaries for nutritional therapy, will optimise the efficacy of nutritional assessment and support in cancer patients.
authors.affiliation: Centre of Nutrition and Metabolism, Institute of Molecular Medicine, Faculty of Medicine, University of Lisbon, Portugal. p.ravasco@fm.ul.pt
authors.forename: P
authors.initials: P
authors.lastname: Ravasco
authors.forename: I
authors.initials: I
authors.lastname: Monteiro-Grillo
authors.forename: P M
authors.initials: PM
authors.lastname: Vidal
authors.forename: M E
authors.initials: ME
authors.lastname: Camilo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D004032:Diet; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000532:radiotherapy*; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009752:Nutritional Status / Q000528:radiation effects*; D011446:Prospective Studies; D015431:Weight Loss / Q000528:radiation effects