title: Identification of a high-risk group among patients with oral cavity squamous cell carcinoma and pT1-2N0 disease.
abstract: OBJECTIVE
  In the American Joint Committee on Cancer 2010 classification system, pT1-2N0 oral cavity squamous cell carcinoma (OSCC) is considered an early-stage cancer treatable with surgery alone (National Comprehensive Cancer Network 2010 guidelines). Our aim was to evaluate the feasibility of surgery alone for pT1-2N0 OSCC patients.
  
  
  METHODS
  Among 1279 previously untreated OSCC patients referred to our hospital between January 1996 and May 2008, we identified 457 consecutive patients with pT1-2N0 disease. All had radical tumor excision with neck dissection. A total of 387 patients showing pathologic margins greater than 4 mm and treated by surgery alone were included in the final analysis. All were followed up for at least 24 months after surgery or until death. The 5-year rates of control, distant metastasis, and survival were the main outcome measures.
  
  
  RESULTS
  The 5-year rates in the entire group of pT1-2N0 patients were as follows: local control, 91%; neck control, 92%; distant metastases, 1%; disease-free survival, 85%; disease-specific survival, 93%; and overall survival, 84%. Multivariate analysis identified poor differentiation and pathologic tumor depth of 4 mm or greater as independent risk factors for neck control, disease-free survival, and disease-specific survival. A scoring system using poor differentiation and tumor depth was formulated to define distinct prognostic groups. The presence of both poorly differentiated tumors and a tumor depth of 4 mm or greater resulted in significantly poorer 5-year neck control (p < 0.0001), disease-free (p < 0.0001), disease-specific (p < 0.0001), and overall survival (p = 0.0046) rates.
  
  
  CONCLUSIONS
  The combination of poor differentiation and pathologic tumor depth of 4 mm or greater identified a subset of pT1-2N0 OSCC patients with poor outcome, who may have clinical benefit from postoperative adjuvant radiotherapy.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chun-Ta
authors.initials: CT
authors.lastname: Liao
authors.forename: Chien-Yu
authors.initials: CY
authors.lastname: Lin
authors.forename: Kang-Hsing
authors.initials: KH
authors.lastname: Fan
authors.forename: Hung-Ming
authors.initials: HM
authors.lastname: Wang
authors.forename: Shu-Hang
authors.initials: SH
authors.lastname: Ng
authors.forename: Li-Yu
authors.initials: LY
authors.lastname: Lee
authors.forename: Chuen
authors.initials: C
authors.lastname: Hsueh
authors.forename: I-How
authors.initials: IH
authors.lastname: Chen
authors.forename: Shiang-Fu
authors.initials: SF
authors.lastname: Huang
authors.forename: Chung-Jan
authors.initials: CJ
authors.lastname: Kang
authors.forename: Tzu-Chen
authors.initials: TC
authors.lastname: Yen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery*; D018572:Disease-Free Survival; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D037981:Neck Dissection; D009367:Neoplasm Staging; D018714:Radiotherapy, Adjuvant; D015996:Survival Rate; D016896:Treatment Outcome; D047368:Tumor Burden