title: Usefulness of homocysteine as a cancer marker: total thiol compounds and folate levels in untreated lung cancer patients.
abstract: BACKGROUND
  Apart from being a risk factor for atherosclerotic cardiovascular diseases, the latest research suggests homocysteine as a marker for cancer. We aimed to explore the clinical utility of plasma homocysteine levels as a marker in lung cancer.
  
  
  METHODS
  Changes in serum total thiols and folate levels were investigated in newly diagnosed untreated lung cancer patients (n = 37) and compared with healthy controls (n = 26). Fluorometric HPLC methods were used for the determination of thiols. Other parameters were determined with commercial diagnostic kits.
  
  
  RESULTS
  Increased total homocysteine (t-Hcy), decreased total glutathione (t-GSH) and folate levels were observed in lung cancer patients compared with healthy controls. Total levels of thiols and folate did not show any significant difference between SCLC and NSCLC patients. However, there were significantly higher t-Hcy, lower t-GSH and folate levels in the advanced-stage group compared with controls. Prevalence of hyperhomocysteinemia was 65% in lung cancer patients when 12 micromol/l were taken as a cut-off value for t-Hcy levels.
  
  
  CONCLUSIONS
  Homocysteine is suggested as a marker for several types of cancer, but our result did not support this hypothesis for lung cancer. Although higher homocysteine levels were observed in the present study, further investigation in the larger cancer population would clarify the importance of homocysteine as a cancer marker.
authors.affiliation: Gazi University, Faculty of Pharmacy, Department of Biochemistry, Etiler-Ankara, Turkey. yesim@gazi.edu.tr
authors.forename: Yeşim
authors.initials: Y
authors.lastname: Ozkan
authors.forename: Sevgi
authors.initials: S
authors.lastname: Yardim-Akaydin
authors.forename: Hikmet
authors.initials: H
authors.lastname: Firat
authors.forename: Emel
authors.initials: E
authors.lastname: Calişkan-Can
authors.forename: Sadik
authors.initials: S
authors.lastname: Ardiç
authors.forename: Bolkan
authors.initials: B
authors.lastname: Simşek
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood / Q000473:pathology; D018288:Carcinoma, Small Cell / Q000097:blood / Q000473:pathology; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005470:Fluorometry; D005492:Folic Acid / Q000097:blood*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D013438:Sulfhydryl Compounds / Q000097:blood*
chemical_list: D014408:Biomarkers, Tumor; D013438:Sulfhydryl Compounds; D006710:Homocysteine; D005492:Folic Acid