title: Prognostic significance of bone invasion for oral cavity squamous cell carcinoma considered T1/T2 by American joint committee on cancer size criteria.
abstract: BACKGROUND
  It is unclear whether bone invasion in small oral cavity squamous cell carcinomas (OCSCC) results in worse prognosis.
  
  
  METHODS
  Two hundred fifty-four patients with OCSCC were identified and divided into 3 cohorts: (1) ≤4 cm with no bone invasion; (2) ≤4 cm with bone invasion; and (3) ≥4 cm or other factors (eg, skin invasion, deep muscle invasion) that would qualify for American Joint Committee on Cancer (AJCC) T4 classification aside from bone invasion. Depth of bone invasion (none, cortical, or medullary) was also recorded.
  
  
  RESULTS
  Cohorts 1 and 2 had similar outcomes. Cohort 3 had lower rates of regional control (p = .04), disease-specific survival (DSS; p < .01), and overall survival (OS; p < .01). On multivariate analysis, margin status and medullary bone invasion were associated with worse outcomes.
  
  
  CONCLUSIONS
  Bone invasion does not seem to significantly influence outcomes in patients with small primary tumors treated with surgery/radiation. Medullary bone invasion seems to result in reduced rates of control and survival.
authors.affiliation: Department of Radiation Oncology, University of North Carolina Hospitals, Chapel Hill, North Carolina.
authors.forename: David
authors.initials: D
authors.lastname: Fried
authors.forename: Brandon
authors.initials: B
authors.lastname: Mullins
authors.forename: Mark
authors.initials: M
authors.lastname: Weissler
authors.forename: Carol
authors.initials: C
authors.lastname: Shores
authors.forename: Adam
authors.initials: A
authors.lastname: Zanation
authors.forename: Trevor
authors.initials: T
authors.lastname: Hackman
authors.forename: William
authors.initials: W
authors.lastname: Shockley
authors.forename: Neil
authors.initials: N
authors.lastname: Hayes
authors.forename: Bhishamjit S
authors.initials: BS
authors.lastname: Chera
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology* / Q000601:surgery* / Q000628:therapy; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D063168:Mandibular Osteotomy / Q000379:methods; D009062:Mouth Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery* / Q000628:therapy; D009367:Neoplasm Staging; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D014481:United States
keywords: bone invasion; oral cavity; squamous cell carcinoma; staging