title: YKL-40 tissue expression and plasma levels in patients with ovarian cancer.
abstract: BACKGROUND
  YKL-40 (chitinase-3-like-1) is a member of "mammalian chitinase-like proteins". The protein is expressed in many types of cancer cells and the highest plasma YKL-40 levels have been found in patients with metastatic disease, short recurrence/progression-free intervals, and short overall survival. The aim of the study was to determine the expression of YKL-40 in tumor tissue and plasma in patients with borderline ovarian tumor or epithelial ovarian cancer (OC), and investigate prognostic value of this marker.
  
  
  METHODS
  YKL-40 protein expression was determined by immunohistochemistry in tissue arrays from 181 borderline tumors and 473 OC. Plasma YKL-40 was determined by ELISA in preoperative samples from 19 patients with borderline tumor and 76 OC patients.
  
  
  RESULTS
  YKL-40 protein expression was found in cancer cells, tumor associated macrophages, neutrophils and mast cells. The tumor cell expression was higher in OC than in borderline tumors (p = 0.001), and associated with FIGO stage (p < 0.0001) and histological subtype (p = 0.0009). Positive YKL-40 expression (>or= 5% staining) was not associated with reduced survival. Plasma YKL-40 was also higher in patients with OC than in patients with borderline tumors (p < 0.0001), and it was positively correlated to serum CA-125 (p < 0.0001) and FIGO stage (p = 0.0001). Univariate Cox analysis of plasma YKL-40 showed association with overall survival (p < 0.0001). Multivariate Cox analysis, including plasma YKL-40, serum CA125, FIGO stage, age and radicality after primary surgery as variables, showed that elevated plasma YKL-40 was associated with a shorter survival (HR = 2.13, 95% CI: 1.40-3.25, p = 0.0004).
  
  
  CONCLUSIONS
  YKL-40 in OC tissue and plasma are related to stage and histology, but only plasma YKL-40 is a prognostic biomarker in patients with OC.
authors.affiliation: Department of Virus, Hormones and Cancer, Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen, Denmark. hogdall@dadlnet.dk
authors.forename: Estrid V S
authors.initials: EV
authors.lastname: Høgdall
authors.forename: Merete
authors.initials: M
authors.lastname: Ringsholt
authors.forename: Claus K
authors.initials: CK
authors.lastname: Høgdall
authors.forename: Ib Jarle
authors.initials: IJ
authors.lastname: Christensen
authors.forename: Julia S
authors.initials: JS
authors.lastname: Johansen
authors.forename: Susanne K
authors.initials: SK
authors.lastname: Kjaer
authors.forename: Jan
authors.initials: J
authors.lastname: Blaakaer
authors.forename: Lene
authors.initials: L
authors.lastname: Ostenfeld-Møller
authors.forename: Paul A
authors.initials: PA
authors.lastname: Price
authors.forename: Lise H
authors.initials: LH
authors.lastname: Christensen
mesh_terms: D054392:Adipokines; D000328:Adult; D000368:Aged; D000071451:Chitinase-3-Like Protein 1; D005260:Female; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic; D006023:Glycoproteins / Q000097:blood* / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D037102:Lectins; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism; D011379:Prognosis; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D037102:Lectins