title: Squamous cell carcinomas of the mandibular alveolus: analysis of prognostic factors.
abstract: BACKGROUND
  To assess the effect of clinicopathologic factors on local tumor control and survival in patients with mandibular alveolar carcinoma.
  
  
  METHODS
  Fifty patients with mandibular alveolar carcinoma treated surgically were included in this study. There were 3 patients with T1, 25 with T2, 5 with T3, and 17 with T4 disease. Clinical evidence of bone invasion was noted in 47 patients. A hemi- or segmental mandibulectomy was performed on 37 patients, whereas 10 patients had a marginal mandibulectomy. The impact of clinicopathologic variables on local tumor control and patient survival was assessed by univariate analysis. Variables included T and N stage, dental extraction, treatment modality, tumor differentiation, nodal status, surgical margin, and bone invasion.
  
  
  RESULTS
  Eleven patients (22%) develop recurrent disease, including 8 local recurrences, 1 neck, and 2 distant metastases. Overall, the 5-year actuarial rates of local control and disease-specific survival were 85 and 73%, respectively. Most local recurrences after surgical treatment were caused by inadequate resection margins. When resection margins were negative, the survival and local control rate were significantly better than when there were positive resection margins (survival, 91 vs. 11%; local control, 100 vs. 49%; p < 0.01). Neither T and N stages, clinical stage, tumor differentiation, dental extraction, bone invasion, extent of bone resection, nor treatment modality influenced outcome.
  
  
  CONCLUSIONS
  The status of surgical margins was of major importance for the outcome of patients with gingival carcinoma of the mandible.
authors.affiliation: First Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Niigata University, Niigata, Japan. shingaki@dent.niigata-u.ac.jp
authors.forename: Susumu
authors.initials: S
authors.lastname: Shingaki
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nomura
authors.forename: Masahito
authors.initials: M
authors.lastname: Takada
authors.forename: Tadaharu
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Ichirou
authors.initials: I
authors.lastname: Suzuki
authors.forename: Tamio
authors.initials: T
authors.lastname: Nakajima
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000401:mortality* / Q000556:secondary / Q000601:surgery; D005260:Female; D006258:Head and Neck Neoplasms / Q000401:mortality / Q000556:secondary; D006801:Humans; D008297:Male; D008334:Mandible / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D018307:Neoplasms, Squamous Cell / Q000175:diagnosis* / Q000401:mortality* / Q000556:secondary / Q000601:surgery; D011379:Prognosis; D016019:Survival Analysis