title: Bioelectrical impedance phase angle in clinical practice: implications for prognosis in stage IIIB and IV non-small cell lung cancer.
abstract: BACKGROUND
  A frequent manifestation of advanced lung cancer is malnutrition, timely identification and treatment of which can lead to improved patient outcomes. Bioelectrical impedance analysis (BIA) is an easy-to-use and non-invasive technique to evaluate changes in body composition and nutritional status. We investigated the prognostic role of BIA-derived phase angle in advanced non-small cell lung cancer (NSCLC).
  
  
  METHODS
  A case series of 165 stages IIIB and IV NSCLC patients treated at our center. The Kaplan Meier method was used to calculate survival. Cox proportional hazard models were constructed to evaluate the prognostic effect of phase angle, independent of stage at diagnosis and prior treatment history.
  
  
  RESULTS
  93 were males and 72 females. 61 had stage IIIB disease at diagnosis while 104 had stage IV. The median phase angle was 5.3 degrees (range = 2.9 - 8). Patients with phase angle <or= 5.3 had a median survival of 7.6 months (95% CI: 4.7 to 9.5; n = 81), while those with > 5.3 had 12.4 months (95% CI: 10.5 to 18.7; n = 84); (p = 0.02). After adjusting for age, stage at diagnosis and prior treatment history we found that every one degree increase in phase angle was associated with a relative risk of 0.79 (95% CI: 0.64 to 0.97, P = 0.02).
  
  
  CONCLUSIONS
  We found BIA-derived phase angle to be an independent prognostic indicator in patients with stage IIIB and IV NSCLC. Nutritional interventions targeted at improving phase angle could potentially lead to an improved survival in patients with advanced NSCLC.
authors.affiliation: Cancer Treatment Centers of America (CTCA) at Midwestern Regional Medical Center, Zion, IL 60099, USA. gupta_digant@yahoo.com
authors.forename: Digant
authors.initials: D
authors.lastname: Gupta
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Lammersfeld
authors.forename: Pankaj G
authors.initials: PG
authors.lastname: Vashi
authors.forename: Jessica
authors.initials: J
authors.lastname: King
authors.forename: Sadie L
authors.initials: SL
authors.lastname: Dahlk
authors.forename: James F
authors.initials: JF
authors.lastname: Grutsch
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Lis
mesh_terms: D000328:Adult; D000368:Aged; D001823:Body Composition; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000401:mortality; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009752:Nutritional Status; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate