title: Serum YKL-40 predicts relapse-free and overall survival in patients with American Joint Committee on Cancer stage I and II melanoma.
abstract: OBJECTIVE
  To evaluate the novel tumor biomarker YKL-40 in serial serum samples from patients with American Joint Committee on Cancer (AJCC) stage I and II melanoma from the time of diagnosis and during routine follow-up. Macrophages, neutrophils, and cancer cells secrete YKL-40, and a high serum level has been associated with poor prognosis in patients with several cancer types.
  
  
  METHODS
  Serum samples from 234 patients with stage I (n = 162) and II (n = 72) melanoma were analyzed for YKL-40 by enzyme-linked immunosorbent assay. Serial samples were obtained before definitive primary surgery and during follow-up.
  
  
  RESULTS
  After a median follow-up period of 66 months (range, 1 to 97 months), 41 relapses (18%) and 39 deaths (17%) were observed. Serum YKL-40 treated as an updated continuous covariate were analyzed together with the covariates sex, age, primary tumor site, ulceration, thickness, Clark level and histologic subtype in a Cox proportional hazard model. Serum YKL-40 was an independent prognostic factor of relapse-free survival (hazard ratio [HR], 1.6; 95% CI, 1.1 to 2.5; P = .03) and overall survival (HR, 1.8; 95% CI, 1.2 to 2.6; P = .002) together with thickness and ulceration. The serum level of YKL-40 (dichotomized as normal or elevated) at the time of diagnosis was also an independent prognostic factor for overall survival (HR, 3.6, 95% CI, 1.7 to 7.7; P = .001).
  
  
  CONCLUSIONS
  Serum YKL-40 may be an early biomarker of relapse and survival in patients with AJCC stage I and II melanoma. Serum YKL-40 may also be useful for patient stratification and follow-up in clinical trials. Our results need confirmation in an independent study.
authors.affiliation: Department of Oncology, Aarhus University Hospital, Norrebrogade 44, 8000 Aarhus C, Denmark. hesch@as.aaa.dk
authors.forename: Henrik
authors.initials: H
authors.lastname: Schmidt
authors.forename: Julia S
authors.initials: JS
authors.lastname: Johansen
authors.forename: Pia
authors.initials: P
authors.lastname: Sjoegren
authors.forename: Ib J
authors.initials: IJ
authors.lastname: Christensen
authors.forename: Boe S
authors.initials: BS
authors.lastname: Sorensen
authors.forename: Kirsten
authors.initials: K
authors.lastname: Fode
authors.forename: Jorn
authors.initials: J
authors.lastname: Larsen
authors.forename: Hans
authors.initials: H
authors.lastname: von der Maase
mesh_terms: D054392:Adipokines; D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D000071451:Chitinase-3-Like Protein 1; D018572:Disease-Free Survival; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D037102:Lectins; D008297:Male; D008545:Melanoma / Q000473:pathology*; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D012878:Skin Neoplasms / Q000473:pathology*
chemical_list: D054392:Adipokines; D014408:Biomarkers, Tumor; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D037102:Lectins