title: Predictive and prognostic significance of sodium levels in patients with NSCLC treated by erlotinib.
abstract: BACKGROUND
  Hyponatremia is a well-known phenomenon in cancer patients. The aim of our retrospective study was to assess the relationship of natremia levels to predict treatment with erlotinib and also to assess the prognosis of patients with hyponatremia.
  
  
  METHODS
  We analyzed data of 544 patients with advanced-stage non-small cell lung cancer (NSCLC) treated with erlotinib.
  
  
  RESULTS
  Hyponatremia was measured in 21.5 % of patients before treatment with erlotinib. We found a significant increase in the effectiveness of treatment with erlotinib in patients with normal levels of sodium to hyponatremic patients. Progression-free survival (PFS) and overall survival (OS) were also significantly higher in patients with normal natremia. Multivariate Cox model analysis demonstrated that natremia was an independent factor for PFS and OS.
  
  
  CONCLUSIONS
  We reported hyponatremia not only as a prognostic marker in NSCLC patients but also as predictive marker of erlotinib treatment efficacy, being an independent factor at the present large retrospective study. Its possible effect in clinical practice is bigger thanks the simple possibility of testing of hyponatremia and the low cost of this biomarker.
authors.affiliation: Department of Pneumology and Phthisiology, Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic svatonm@gmail.com.
authors.forename: Martin
authors.initials: M
authors.lastname: Svaton
authors.affiliation: Department of Oncology and Radiotherapy, Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Fiala
authors.affiliation: Department of Pneumology and Phthisiology, Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic.
authors.forename: Milos
authors.initials: M
authors.lastname: Pesek
authors.affiliation: Department of Pneumology and Phthisiology, Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic.
authors.forename: Frantisek
authors.initials: F
authors.lastname: Bruha
authors.affiliation: Department of Pathology, Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Mukensnabl
authors.affiliation: Department of Chemistry and Biochemistry, Faculty of Medicine in Pilsen, Charles University in Prague, Prague, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Racek
authors.affiliation: Centre for Applied Genomics of Solid Tumours (CEGES), Genomac Research Institute, Prague, Czech Republic.
authors.forename: Marek
authors.initials: M
authors.lastname: Minarik
authors.affiliation: Institute of Biostatistics and Analyses, Masaryk University, Brno, Czech Republic.
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Bortlicek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood / Q000188:drug therapy* / Q000401:mortality; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D000069347:Erlotinib Hydrochloride; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000097:blood / Q000175:diagnosis*; D008175:Lung Neoplasms / Q000097:blood / Q000188:drug therapy / Q000401:mortality; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011799:Quinazolines / Q000627:therapeutic use*; D012189:Retrospective Studies; D012964:Sodium / Q000097:blood*; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D012964:Sodium; D000069347:Erlotinib Hydrochloride; D066246:ErbB Receptors
keywords: Hyponatremia; NSCLC; OS; PFS; predictive marker; prognosis