title: Serum YKL-40 Levels in Patients with Gastric Cancer.
abstract: OBJECTIVE
  YKL-40 is secreted by several types of tumors. Increased serum YKL-40 levels have been reported in prostate, glioblastoma, breast and colorectal cancers. Determination of YKL-40 levels may serve as a valuable biomarker for the diagnosis and treatment of gastric cancer. The purpose of this study was to determine the serum YKL-40 levels expressed in gastric carcinomas.
  
  
  METHODS
  Between 2009 and 2011, we retrospectively reviewed 100 patients with gastric cancer and compared their serum samples to 75 healthy volunteers. YKL-40 levels were determined by an enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  We found significantly higher serum levels of YKL-40 in patients with gastric cancer compared to the healthy population (P < 0.0001). We also found significant differences in serum YKL-40 levels between female and male patients with gastric cancer (P < 0.01).
  
  
  CONCLUSIONS
  YKL-40 is over-expressed in gastric cancer, suggesting a more aggressive phenotype. YKL-40 may be a useful serum biomarker for gastric cancer identification, and future studies should focus on the role of YKL-40 in the tumorigenesis of gastric cancer and responsiveness toward treatment.
authors.affiliation: Department of General Surgery, Yuzuncu Yil University Medical Faculty, Van, Turkey.
authors.forename: Veyis
authors.initials: V
authors.lastname: Itik
authors.forename: Ozgur
authors.initials: O
authors.lastname: Kemik
authors.forename: Ahu
authors.initials: A
authors.lastname: Kemik
authors.forename: A Cumhur
authors.initials: AC
authors.lastname: Dulger
authors.forename: Aziz
authors.initials: A
authors.lastname: Sümer
authors.forename: Yasemin Usul
authors.initials: YU
authors.lastname: Soyoral
authors.forename: Huseyin
authors.initials: H
authors.lastname: Begenik
authors.forename: Sevim
authors.initials: S
authors.lastname: Purisa
authors.forename: Cetin
authors.initials: C
authors.lastname: Kotan
keywords: YKL-40; gastric cancer