title: Haptoglobin alpha-subunit and hepatocyte growth factor can potentially serve as serum tumor biomarkers in small cell lung cancer.
abstract: BACKGROUND
  Small cell lung cancer (SCLC) frequently presents as metastatic disease. It would be useful to detect serum tumor biomarkers at an earlier stage in order to improve the overall survival.
  
  
  METHODS
  Serum samples from SCLC patients (6 limited disease, 7 extensive disease, 4 relapsed disease, 4 no evidence of disease post-treatment) and 5 normal controls were used to identify tumor biomarkers utilizing proteomics. Serum hepatocyte growth factor was also studied using standard ELISA.
  
  
  RESULTS
  Utilizing MALDI-TOF-Mass Spectrometry (MS) based protein identification techniques, a SCLC specific overexpressed protein was identified to be haptoglobin alpha-subunit, with its serum level correlating with the disease stage. The mean level of alpha-haptoglobin was increased in SCLC serum as compared to the normal controls. Serum HGF was also studied as potential tumor biomarker and was found to correlate with the disease status. Either serum alpha-haptoglobin relative level (above 1.9 U), or HGF level (above 500 pg/ml) was associated with a trend towards worse survival.
  
  
  CONCLUSIONS
  Our current findings suggest that serum levels of alpha-haptoglobin and HGF may serve as useful serum tumor biomarkers in SCLC. It would now also be useful to determine if these serum biomarkers are altered in response to therapy for this disease.
authors.affiliation: Department of Medicine, Center for Molecular Stress Response, Boston University School of Medicine, 88 East Newton Street, Boston, MA 02118, USA.
authors.forename: Ajit
authors.initials: A
authors.lastname: Bharti
authors.forename: Patrick C
authors.initials: PC
authors.lastname: Ma
authors.forename: Gautam
authors.initials: G
authors.lastname: Maulik
authors.forename: Rajeev
authors.initials: R
authors.lastname: Singh
authors.forename: Eshan
authors.initials: E
authors.lastname: Khan
authors.forename: Arthur T
authors.initials: AT
authors.lastname: Skarin
authors.forename: Ravi
authors.initials: R
authors.lastname: Salgia
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D018288:Carcinoma, Small Cell / Q000097:blood* / Q000473:pathology; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006242:Haptoglobins / Q000378:metabolism*; D017228:Hepatocyte Growth Factor / Q000096:biosynthesis / Q000097:blood*; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000473:pathology; D009367:Neoplasm Staging; D010865:Pilot Projects; D011379:Prognosis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; C485359:HP protein, human; D006242:Haptoglobins; D017228:Hepatocyte Growth Factor