title: A combined prognostic factor for improved risk stratification of patients with oral cancer.
abstract: OBJECTIVE
  We aimed to identify a combined prognostic factor for predicting better performance in risk stratification.
  
  
  METHODS
  We reviewed the clinical and pathological variables of 316 patients with oral squamous cell carcinoma (OSCC) who underwent surgery. To identify a combined predictor, principal component analysis (PCA) was performed.
  
  
  RESULTS
  Univariate analysis showed that the independent prognostic variables for overall survival (OS) were pathologic T stage (T1 vs T4, HR = 1.99, 95% CI: = 1.083-3.675, P = 0.026) and pathologic N stage (N0 vs N2, HR=1.90, 95% CI: = 1.17-3.08, P = 0.008). In the multivariate analysis, only pathologic T stage was significant (P = 0.006 and P = 0.007); however, the multivariate model was not significant (P = 0.191). The multivariate model became significant by including lymph node ratio (LNR) instead of pathologic N stage (P = 0.0025 in numeric LNR, P = 0.0007 in categorized LNR). Also, the performance of prediction model was improved by a combined prognostic factor (P = 0.0002).
  
  
  CONCLUSIONS
  The newly identified combined prognostic factor included resection margin, differentiation, and LNR, and they were insignificant factors independently except for LNR. This combined prognostic factor showed a good performance although it did not include molecular markers; therefore, it may be used conveniently for risk stratification of patients with OSCC by combining only clinical information.
authors: BK21 PLUS Project, College of Dentistry, Yonsei University, Seoul, Korea.
authors: K-Y
authors: KY
authors: Kim
authors: Department of pathology, Yanbian University medical college, Yanji city, China.
authors: X
authors: X
authors: Zhang
authors: Department of Oral and Maxillofacial Surgery, College of Dentistry, Yonsei University, Seoul, Korea.
authors: S-M
authors: SM
authors: Kim
authors: Department of Oral and Maxillofacial Surgery, College of Dentistry, Yonsei University, Seoul, Korea.
authors: B-D
authors: BD
authors: Lee
authors: Department of Oral and Maxillofacial Surgery, College of Dentistry, Yonsei University, Seoul, Korea.
authors: I-H
authors: IH
authors: Cha
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D009367:Neoplasm Staging; D025341:Principal Component Analysis; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D016019:Survival Analysis; D055815:Young Adult
keywords: clinical diagnosis; combined prognostic factor; lymph node ratio; oral cancer; risk stratification