title: Elevated pretreatment serum concentration of YKL-40-An independent prognostic biomarker for poor survival in patients with metastatic nonsmall cell lung cancer.
abstract: BACKGROUND
  The glycoprotein YKL-40 is synthesized both by cancer cells and by tumor-associated macrophages and plays a functional role in tumor progression. Consequently, high serum YKL-40 levels have been associated with a poor prognosis in patients with several cancer types. However, the role of YKL-40 has not been established in nonsmall cell lung cancer (NSCLC).
  
  
  METHODS
  Pretreatment serum levels of YKL-40 were determined in 189 patients with NSCLC (143 men and 46 women; median age, 62 years;, age range, 41-76 years). Twelve percent of patients had stage IIIB disease, and 88% had stage IV disease. Ninety-eight patients received combined gemcitabine and vinorelbine, and 91 received combined gemcitabine, vinorelbine, and cisplatin as first-line chemotherapy. The median overall survival was 37 weeks.
  
  
  RESULTS
  Patients had a median serum YKL-40 level of 209 ng/mL (range, 19-2153 ng/mL). No correlation was observed between overall survival and the type of chemotherapy regimen used, tumor stage, sex, or histologic types. Patients with high serum YKL-40 levels (greater than the median level for all patients [209 ng/mL]) had a significantly shorter survival than patients with serum YKL-40 levels below the median (median survival, 32 weeks vs 41 weeks; P = .007). In multivariate analysis, the serum YKL-40 level, the presence of bone lesions, and the serum lactate dehydrogenase level were independent, statistically significant prognostic factors.
  
  
  CONCLUSIONS
  The pretreatment serum YKL-40 level was identified as a new, independent prognostic biomarker in patients with metastatic NSCLC and may help to determine the individual prognosis of these patients.
authors.affiliation: Department of Oncology, Hematology, and Bone Marrow Transplantation with Section Pneumology, Hubertus Wald Tumor Center, University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. i.thoem@uke.uni-hamburg.de
authors.forename: Ina
authors.initials: I
authors.lastname: Thöm
authors.forename: Birte
authors.initials: B
authors.lastname: Andritzky
authors.forename: Gunter
authors.initials: G
authors.lastname: Schuch
authors.forename: Iris
authors.initials: I
authors.lastname: Burkholder
authors.forename: Lutz
authors.initials: L
authors.lastname: Edler
authors.forename: Julia S
authors.initials: JS
authors.lastname: Johansen
authors.forename: Carsten
authors.initials: C
authors.lastname: Bokemeyer
authors.forename: Udo
authors.initials: U
authors.lastname: Schumacher
authors.forename: Eckart
authors.initials: E
authors.lastname: Laack
mesh_terms: D054392:Adipokines; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood* / Q000401:mortality / Q000473:pathology; D000071451:Chitinase-3-Like Protein 1; D018572:Disease-Free Survival; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D037102:Lectins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011379:Prognosis
chemical_list: D054392:Adipokines; D014408:Biomarkers, Tumor; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D037102:Lectins