title: Clinical evidence of field cancerization in patients with oral cavity cancer in a betel quid chewing area.
abstract: OBJECTIVE
  We sought to investigate whether there is evidence of field cancerization in patients with oral cavity squamous cell carcinoma (OSCC) enrolled in a betel quid chewing area. We also assessed whether betel quid chewing is an independent risk factor for field cancerization in OSCC patients.
  
  
  METHODS
  We retrospectively examined the records of 1570 OSCC patients who underwent radical tumor resection between 1996 and 2011. A total of 1243 study participants (79%) had a positive history of betel quid chewing before surgery. Of the 767 patients treated with surgery alone, 599 (78%) were preoperative chewers, whereas a history of preoperative betel quid chewing was identified in 644 (80%) of the 803 patients who received adjuvant therapy. The 5-year control, survival, and second primary tumors (SPTs) rates served as the main outcome measures.
  
  
  RESULTS
  Regardless of the treatment modality, more than 70% of the SPTs were located in the oral cavity or soft palate. Despite a similar risk profile in terms of tumor depth, lymph node metastasis, and pathological margin status, preoperative chewers showed a significantly higher incidence of 5-year SPTs and local recurrences compared with non-chewers. Moreover, multivariate analysis demonstrated that preoperative betel quid chewing was an independent prognostic factor for 5-year local control and SPTs occurrence rates.
  
  
  CONCLUSIONS
  Our results demonstrate that preoperative betel quid chewers had a higher incidence of local recurrence and SPTs than non-chewers, suggesting that field cancerization may occur in OSCC patients with a history of betel quid chewing.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Chun-Ta
authors.initials: CT
authors.lastname: Liao
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Wallace
authors.affiliation: Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Pathology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Li-Yu
authors.initials: LY
authors.lastname: Lee
authors.affiliation: Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Pathology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Chuen
authors.initials: C
authors.lastname: Hsueh
authors.affiliation: Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Radiation Oncology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Chien-Yu
authors.initials: CY
authors.lastname: Lin
authors.affiliation: Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Radiation Oncology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Kang-Hsing
authors.initials: KH
authors.lastname: Fan
authors.affiliation: Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Medical Oncology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Hung-Ming
authors.initials: HM
authors.lastname: Wang
authors.affiliation: Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Diagnostic Radiology, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Shu-Hang
authors.initials: SH
authors.lastname: Ng
authors.affiliation: Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Lin
authors.affiliation: Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Chung-Kan
authors.initials: CK
authors.lastname: Tsao
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: I-How
authors.initials: IH
authors.lastname: Chen
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Shiang-Fu
authors.initials: SF
authors.lastname: Huang
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC.
authors.forename: Chung-Jan
authors.initials: CJ
authors.lastname: Kang
authors.affiliation: Department of Head and Neck Oncology Group, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC; Department of Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan, ROC. Electronic address: yen1110@adm.cgmh.org.tw.
authors.forename: Tzu-Chen
authors.initials: TC
authors.lastname: Yen
mesh_terms: D001114:Areca; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000209:etiology / Q000473:pathology* / Q000601:surgery
keywords: Betel quid chewing; Field cancerization; Oral cavity cancer; Prognosis; Squamous cell carcinoma