title: The place of YKL-40 in non-small cell lung cancer.
abstract: BACKGROUND
  Despite varies treatment options, the survival rate of non-small cell lung cancer (NSCLC) is less than 1%. If biological behaviour of any cancer could be known, the information would potentially tailor the clinical work-up, assessment and treatment. The prognostic value of serum YKL-40 level has been investigated in different types of cancer and showed poor prognostic indication with more aggressive clinical course. We studied the role of serum YKL-40 levels in patients with NSCLC to determine the stage.
  
  
  METHODS
  Serum YKL-40 levels in venous blood samples of 55 patients was studied. 49 (89.1%) male and 6 (10.9%) female newly diagnosed NSCLC patients whom received neither cancer specific or symptom relieving treatment are enrolled. TNM staging was determined based on the findings of computerized tomography (CT), positron emission tomography (PET), cranial magnetic resonance imaging (MRI), bronchoscopy and mediastinoscopy. The patients with NSCLC were divided into two groups; Group A: stage Ia, Ib, IIa, IIb, Group B: stage IIIa, IIIb and IV.
  
  
  RESULTS
  There was a statistical difference in YKL-40 serum levels between groups (Group A, Group B) when compared (p< 0.05). A medium and statistical correlation was found (r= 0.48; p< 0.01) between YKL-40 levels and age.
  
  
  CONCLUSIONS
  YKL-40 levels in advanced stage NSCLC (stage III, IV) was found to be significantly high compared to early stage. It should be kept in mind that when YKL levels are high, higher stages of the disease should be suspected and future tests should be performed.
authors.forename: Ayşegül
authors.initials: A
authors.lastname: Kırankaya Güneş
authors.affiliation: Clinic of Chest Diseases, Istanbul Yedikule Chest Diseases and Chest Surgery Training and Research Hospital, Istanbul, Turkey. suleeyhan@gmail.com.
authors.forename: Şule
authors.initials: Ş
authors.lastname: Gül
authors.forename: Nuri
authors.initials: N
authors.lastname: Tutar
authors.forename: Mehmet Akif
authors.initials: MA
authors.lastname: Özgül
authors.forename: Erdoğan
authors.initials: E
authors.lastname: Çetinkaya
authors.forename: Oğuzhan
authors.initials: O
authors.lastname: Zengi
authors.forename: Hilal
authors.initials: H
authors.lastname: Onaran
mesh_terms: D054392:Adipokines / Q000097:blood*; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood* / Q000473:pathology; D000071451:Chitinase-3-Like Protein 1; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D037102:Lectins / Q000097:blood*; D008175:Lung Neoplasms / Q000097:blood* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis
chemical_list: D054392:Adipokines; D014408:Biomarkers, Tumor; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D037102:Lectins