title: Higher serum nitrate levels are associated with poor survival in lung cancer patients.
abstract: OBJECTIVE
  Angiogenic factors induce tumour growth and angiogenesis which leads to tumour metastasis and a poor survival rate. This study aimed to assess the possible roles of nitric oxide (NO) and vascular endothelial growth factor-A (VEGF-A) in the overall survival of patients with late stage lung cancer.
  
  
  METHODS
  The study was carried out with primary lung carcinoma patients (n=31) and healthy controls (n=15). Pre- and post-cisplatin-based chemotherapy serum nitrite/nitrate levels were measured as nitrite after enzymatic conversion followed by Griess reaction and serum VEGF-A analysis was performed using ELISA. After patient follow-up, survival rates were calculated by using the Kaplan-Meier method [Dudek et al. Cancer Invest 2005; 23(3):193-200].
  
  
  RESULTS
  The serum nitrite/nitrate and VEGF-A levels of lung cancer patients and the control group were 93.7+/-48.9 and 63.7+/-32.2 microM (p=0.018), and 620+/-491 and 255+/-157 pg/mL (p=0.001), respectively. High nitrite/nitrate (>67.2 microM) concentration had statistically significant effects on overall survival (Cox analysis, p=0.026). The overall survival of the lung cancer patients with higher serum nitrate concentrations was significantly less than the ones with lower serum nitrite/nitrate (Kaplan-Meier survival functions test, log rank significance=0.0007).
  
  
  CONCLUSIONS
  Our results suggest that having a high serum nitrite/nitrate concentration is a strong indicator of poor survival for late stage lung cancer patients. However, this conclusion deserves to be elucidated further by using a larger sample size.
authors.affiliation: Uludag University Faculty of Medicine, Department of Biochemistry, Turkey.
authors.forename: Mukaddes
authors.initials: M
authors.lastname: Colakogullari
authors.forename: Engin
authors.initials: E
authors.lastname: Ulukaya
authors.forename: Arzu
authors.initials: A
authors.lastname: Yilmaztepe
authors.forename: Gokhan
authors.initials: G
authors.lastname: Ocakoglu
authors.forename: Meryem
authors.initials: M
authors.lastname: Yilmaz
authors.forename: Mehmet
authors.initials: M
authors.lastname: Karadag
authors.forename: Asuman
authors.initials: A
authors.lastname: Tokullugil
mesh_terms: D000368:Aged; D002277:Carcinoma / Q000097:blood* / Q000401:mortality*; D016022:Case-Control Studies; D004358:Drug Therapy; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000097:blood*; D009573:Nitrites / Q000097:blood; D015996:Survival Rate; D042461:Vascular Endothelial Growth Factor A / Q000097:blood
chemical_list: D009566:Nitrates; D009573:Nitrites; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A