title: Factors influencing the incidence and prognosis of second primary tumors in patients with oral squamous cell carcinoma.
abstract: Although second primary tumors are common in patients with oral squamous cell carcinoma (OSCC), their predisposing factors and treatment guideline remain uncertain.
  
  
  
  Three hundred ninety-four patients with OSCC who received radical surgery from January 2002 to December 2009 were retrospectively reviewed.
  
  
  
  Forty-five patients developed oral second primary tumors. Areca quid chewing, tongue tumors, and nodal metastasis were risk factors for second primary tumors. Multivariate analyses revealed that no second primary tumor (hazard ratio [HR] = 5.046; 95% confidence interval [CI] = 3.704-12.246; p = .003), contralateral neck dissection for ipsilateral second primary tumors (HR = 6.254; 95% CI = 3.027-13.365; p = .007), and postoperative radiotherapy (RT; HR = 3.987; 95% CI = 1.099-10.381; p = .040) were independent favorable prognostic factors.
  
  
  
  Areca quid chewing, tongue tumors, and nodal metastasis predisposed patients with OSCC to second primary tumor development. Elective dissection of the contralateral neck in patients with second primary tumors ipsilateral to index tumors and postoperative RT for eligible patients should always be considered in the management of oral second primary tumors. © 2016 Wiley Periodicals, Inc. Head Neck 38: First-1466, 2016.
authors.affiliation: Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan.|Department of Dentistry, National Taiwan University Hospital, College of Medicine, Taipei, Taiwan.
authors.forename: Hui-Hsin
authors.initials: HH
authors.lastname: Ko
authors.affiliation: Department of Internal Medicine, Far Eastern Memorial Hospital, Taipei, Taiwan.|Department of Chemical Engineering and Materials Science, Yuan-Ze University, Chung-Li, Taiwan.
authors.forename: Shih-Lung
authors.initials: SL
authors.lastname: Cheng
authors.affiliation: Department of Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan.|Department of Dentistry, National Taiwan University Hospital, College of Medicine, Taipei, Taiwan.
authors.forename: Jang-Jaer
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan.|Department of Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan.|Department of Dentistry, National Taiwan University Hospital, College of Medicine, Taipei, Taiwan.|Graduate Institute of Oral Biology, School of Dentistry, National Taiwan University, Taipei, Taiwan.
authors.forename: Hsin-Ming
authors.initials: HM
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology, National Taiwan University Hospital, College of Medicine, Taipei, Taiwan.
authors.forename: Chun-Wei
authors.initials: CW
authors.lastname: Wang
authors.affiliation: Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan. sjcheng56@ntu.edu.tw.|Department of Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan. sjcheng56@ntu.edu.tw.|Department of Dentistry, National Taiwan University Hospital, College of Medicine, Taipei, Taiwan. sjcheng56@ntu.edu.tw.
authors.forename: Shih-Jung
authors.initials: SJ
authors.lastname: Cheng
authors.affiliation: Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan. shkok@ntu.edu.tw.|Department of Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan. shkok@ntu.edu.tw.|Department of Dentistry, National Taiwan University Hospital, College of Medicine, Taipei, Taiwan. shkok@ntu.edu.tw.
authors.forename: Sang-Heng
authors.initials: SH
authors.lastname: Kok
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000628:therapy; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000473:pathology* / Q000628:therapy; D016609:Neoplasms, Second Primary / Q000209:etiology / Q000401:mortality / Q000628:therapy; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D012307:Risk Factors
keywords: areca quid chewing; contralateral neck dissection; irradiation; oral squamous cell carcinoma; second primary tumor