title: A novel statistical prognostic score model that includes serum CXCL5 levels and clinical classification predicts risk of disease progression and survival of nasopharyngeal carcinoma patients.
abstract: BACKGROUND
  Aberrant expression of C-X-C motif chemokine 5 (CXCL5) contributes to the progression of various cancers. This study analyzed the clinical significance of serum CXCL5 (sCXCL5) levels of nasopharyngeal carcinoma (NPC) patients, with the goal of building a novel prognostic score model.
  
  
  METHODS
  Serum samples were collected prior to treatment from 290 NPC patients for the detection of sCXCL5 with ELISA. Half of the patients (n = 145) were randomly assigned to the training set to generate the sCXCL5 cutoff point using receiver operator characteristic (ROC) analysis, while the other half (n = 145) were assigned to the testing set for validation. Associations between sCXCL5 levels and clinical characteristics were analyzed. A prognostic score model was built using independent predictors derived from multivariate analysis. A concordance index (C-Index) was used to evaluate prognostic ability.
  
  
  RESULTS
  The sCXCL5 cutoff point was 0.805 ng/ml. Sex, age, histology, T classification, clinical classification and local recurrence were not associated with sCXCL5 levels. However, sCXCL5 levels were positively associated with N classification, distant metastasis and disease progression (P<0.05). A high sCXCL5 level predicted poor 6-year overall survival (OS), poor 6-year distant metastasis-free survival (DMFS), and poor 6-year progression-free survival (PFS). A prognostic score model was subsequently constructed based on sCXCL5 levels and clinical classification (C-C model), which are independent predictors of OS, DMFS, and PFS, as confirmed by the multivariate analysis. Furthermore, this novel model successfully divided the patients into four risk subgroups in the training set, the testing set and the entire set of patients. The C-Indices were 0.751 and 0.762 for the training set and the testing set, respectively.
  
  
  CONCLUSIONS
  sCXCL5 level was determined to be an independent prognostic factor for NPC patients. The novel statistical C-C model, which includes sCXCL5 levels and clinical classification, could be helpful in predicting the prognosis of NPC patients.
authors.affiliation: Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, Guangzhou, China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Zhang
authors.forename: Weixiong
authors.initials: W
authors.lastname: Xia
authors.forename: Xing
authors.initials: X
authors.lastname: Lu
authors.forename: Rui
authors.initials: R
authors.lastname: Sun
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Lisheng
authors.initials: L
authors.lastname: Zheng
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Ye
authors.forename: Yingna
authors.initials: Y
authors.lastname: Bao
authors.forename: Yanqun
authors.initials: Y
authors.lastname: Xiang
authors.forename: Xiang
authors.initials: X
authors.lastname: Guo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma; D054365:Chemokine CXCL5 / Q000097:blood*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000097:blood* / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D011379:Prognosis; D016016:Proportional Hazards Models; D012306:Risk; D055815:Young Adult
chemical_list: D054365:Chemokine CXCL5