title: Exhaled Breath Condensate pH in Lung Cancer, the Impact of Clinical Factors.
abstract: OBJECTIVE
  Lung cancer may be associated with airway acidification due to enhanced airway inflammation and oxidative stress. Exhaled breath condensate (EBC) pH is a non-invasive indicator of airway acidity; however, it is still unclear how EBC pH changes in lung cancer. The aim of the study was to investigate EBC pH in lung cancer together with clinical variables.
  
  
  METHODS
  Thirty-five patients with lung cancer and 37 control subjects (21 patients with stable COPD and 16 non-COPD smokers) were enrolled. EBC was collected for pH, which was determined with the argon-purging method, compared among the groups and correlated with clinical variables of patients with lung cancer.
  
  
  RESULTS
  No difference was found in EBC pH between patients with lung cancer and control subjects. However, endobronchial tumour localisation, squamous-cell carcinoma subtype and gastro-oesophageal reflux were associated with low EBC pH values. No relationship was observed between EBC pH and the presence of COPD, lung function variables or smoking history.
  
  
  CONCLUSIONS
  Although, EBC pH is unchanged in lung cancer, lower EBC pH values are associated with distinct phenotypes. Our findings could facilitate further research on airway acidity in lung cancer.
authors.affiliation: Department of Pulmonology, Semmelweis University, 1/C Dios arok, Budapest, 1125, Hungary. andras.bikov@gmail.com.
authors.forename: Andras
authors.initials: A
authors.lastname: Bikov
authors.affiliation: Department of Pulmonology, Semmelweis University, 1/C Dios arok, Budapest, 1125, Hungary.
authors.forename: Zsofia
authors.initials: Z
authors.lastname: Lazar
authors.affiliation: Department of Pulmonology, Semmelweis University, 1/C Dios arok, Budapest, 1125, Hungary.
authors.forename: Nora
authors.initials: N
authors.lastname: Gyulai
authors.affiliation: Department of Pulmonology, Semmelweis University, 1/C Dios arok, Budapest, 1125, Hungary.
authors.forename: Marton
authors.initials: M
authors.lastname: Szentkereszty
authors.affiliation: Department of Pulmonology, Semmelweis University, 1/C Dios arok, Budapest, 1125, Hungary.
authors.forename: Gyorgy
authors.initials: G
authors.lastname: Losonczy
authors.affiliation: Department of Pulmonology, Semmelweis University, 1/C Dios arok, Budapest, 1125, Hungary.|National Koranyi Institute for TB and Pulmonology, 1 Piheno ut, Budapest, 1121, Hungary.
authors.forename: Ildiko
authors.initials: I
authors.lastname: Horvath
authors.affiliation: Department of Pulmonology, Semmelweis University, 1/C Dios arok, Budapest, 1125, Hungary.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Galffy
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000378:metabolism*; D000368:Aged; D001944:Breath Tests; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000378:metabolism*; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D005764:Gastroesophageal Reflux / Q000453:epidemiology / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008175:Lung Neoplasms / Q000453:epidemiology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology / Q000378:metabolism*; D055752:Small Cell Lung Carcinoma / Q000453:epidemiology / Q000378:metabolism*; D012907:Smoking / Q000453:epidemiology / Q000378:metabolism*
keywords: Airway acidity; Biomarkers; Breath test; Exhaled breath condensate; Lung cancer