title: Survival analysis of patients with oral squamous cell carcinoma with simultaneous second primary tumors.
abstract: BACKGROUND
  The purpose of this study was to investigate the rate of simultaneous second primary tumor (SPT) in patients with oral squamous cell carcinoma. The survival of patients with simultaneous SPT was also compared with patients without.
  
  
  METHODS
  The presence of SPT was documented along with the patients' demographic data, tumor-related features, and survival status. Kaplan-Meier method was used for survival analysis. Relevant factors influencing the survival were examined by the Cox proportional hazard model.
  
  
  RESULTS
  A total of 897 patients' medical records were obtained. Among them, 43 patients (4.8%) had simultaneous SPT and their prognosis was poorer than that of patients without. The Cox proportional hazard model revealed that patients with simultaneous SPT tended to have a higher probability of death (relative risk [RR], 1.694; p = .015).
  
  
  CONCLUSIONS
  Simultaneous SPT is an independent prognostic factor for patients with oral squamous cell carcinoma. Those with simultaneous SPT have poorer survival when compared to those without.
authors.affiliation: Department of Otolaryngology, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Shuo-Hsiu
authors.initials: SH
authors.lastname: Hsu
authors.forename: Yong-Kie
authors.initials: YK
authors.lastname: Wong
authors.forename: Ching-Ping
authors.initials: CP
authors.lastname: Wang
authors.forename: Chen-Chi
authors.initials: CC
authors.lastname: Wang
authors.forename: Rong-San
authors.initials: RS
authors.lastname: Jiang
authors.forename: Fun-Jou
authors.initials: FJ
authors.lastname: Chen
authors.forename: Shih-An
authors.initials: SA
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001114:Areca / Q000009:adverse effects; D002294:Carcinoma, Squamous Cell / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008409:Mastication; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D016609:Neoplasms, Second Primary / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies
keywords: betel quid; oral cavity cancer; second primary; simultaneous; survival