title: Clinical significance of simultaneous determination of serum tryptophan and tyrosine in patients with lung cancer.
abstract: BACKGROUND
  To explore the clinical significance of serum tyrosine (Tyr) and tryptophan (Trp) in patients with lung cancer, we used a simple and efficient method of high-performance liquid chromatography with fluorescence detection (HPLC-FD) that simultaneously measured serum Trp and Tyr contents.
  
  
  METHODS
  The concentrations of Tyr and Trp were measured simultaneously by HPLC-FD in the sera of 80 patients with lung cancer and 120 healthy controls.
  
  
  RESULTS
  Trp concentrations were significantly lower in patients with lung cancer than in healthy controls (39.26±5.44 vs. 49.93±5.43 µmol/l, respectively; P<0.01), whereas in Tyr concentrations there were no differences with healthy controls (65.38±7.94 vs.66.40±8.55 µmol/l, respectively; P>0.05). In addition, patients in the adenocarcinoma group had significantly lower Trp and Tyr concentrations than those in squamous cell carcinoma group. There was no difference between the early stage and advanced stage of lung cancer.
  
  
  CONCLUSIONS
  Determination of serum Trp and Tyr concentrations can be employed to assist the diagnosis of the histotypes of lung cancer and tumor stage. Tyr and Trp as indexes on the lung cancer diagnostic sensitivity, specificity were 54.9, 62.9% and 82.4, 92.1%, Trp is an important and special index for lung cancer diagnosis of which the specificity of diagnosis of lung cancer is more than 92%.
authors.affiliation: Department of Clinical Laboratory, Second Xiangya Hospital, Central South University, Changsha, P.R. China.
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Ren
authors.forename: Ai-Guo
authors.initials: AG
authors.lastname: Tang
authors.forename: Qian-Xuan
authors.initials: QX
authors.lastname: Zhou
authors.forename: Zhong-Yuan
authors.initials: ZY
authors.lastname: Xiang
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000473:pathology; D000077192:Adenocarcinoma of Lung; D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012680:Sensitivity and Specificity; D014364:Tryptophan / Q000097:blood*; D014443:Tyrosine / Q000097:blood*
chemical_list: D014408:Biomarkers, Tumor; D014443:Tyrosine; D014364:Tryptophan