title: Clinical nodal stage is a significant predictor of outcome in patients with oral cavity squamous cell carcinoma and pathologically negative neck metastases: results of the international consortium for outcome research.
abstract: BACKGROUND
  We aimed to study the importance of clinical N classification (cN) in a subgroup of patients with oral cavity squamous cell carcinoma (OSCC) and pathologically negative neck nodes (pN-).
  
  
  METHODS
  A total of 2,258 patients from 11 cancer centers who underwent neck dissection for OSCC (1990-2011) had pN- disease. The median follow-up was 44 months. 5-year overall survival (OS), disease-specific survival (DSS), disease free survival, local control, locoregional control, and distant metastasis rates were calculated by the Kaplan-Meier method. cN classification and tumor, node, metastasis classification system staging variables were subjected to multivariate analysis.
  
  
  RESULTS
  A total of 345 patients were preoperatively classified as cN+ and 1,913 were classified as cN-. The 5-year OS and DSS of cN- patients were 73.6 and 82.2 %, respectively. The 5-year OS and DSS of cN+ patients were 64.9 and 76.9 %, respectively (p < 0.0001 each). A cN+ classification was a significant predictor of worse OS (p = 0.03) and DSS (p = 0.016), regardless of treatment, depth of invasion, or extent of neck dissection. cN classification was associated with recurrence-free survival (p = 0.01) and locoregional (neck and primary tumor) control (p = 0.004), but not with local (p = 0.19) and distant (p = 0.06) recurrence rates.
  
  
  CONCLUSIONS
  Clinical evidence of neck metastases is an independent predictor of outcome, even in patients with pN- nodes.
authors.affiliation: The Laboratory for Applied Cancer Research, Rambam Medical Center, Haifa, Israel. moranamit@gmail.com
authors.forename: M
authors.initials: M
authors.lastname: Amit
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mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000401:mortality* / Q000556:secondary*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007390:International Agencies; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000401:mortality* / Q000473:pathology*; D037981:Neck Dissection / Q000401:mortality*; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate