title: Improvement in survival of patients with oral cavity squamous cell carcinoma: An international collaborative study.
abstract: BACKGROUND
  An association between the survival of patients with oral cavity squamous cell carcinoma (OCSCC) and advancements in diagnosis and therapy has not been established.
  
  
  METHODS
  This was a retrospective, longitudinal, international, population-based study of 2738 patients who underwent resection of OCSCC during 2 different decades. Characteristics of patients from 7 international cancer centers who received treatment between 1990 and 2000 (group A; n = 735) were compared with patients who received treatment between 2001 and 2011 (group B; n = 2003).
  
  
  RESULTS
  Patients in group B had more advanced tumors and tended to develop distant metastases more frequently than patients in group A (P = .005). More group B patients underwent selective neck dissection and received adjuvant radiotherapy (P < .001). Outcome analysis revealed a significant improvement in 5-year overall survival, from 59% for group A to 70% for group B (P < .001). There was also a significant improvement in disease-specific survival associated with operations performed before and after 2000 (from 69% to 81%, respectively; P < .001). Surgery after 2000, negative margins, adjuvant treatment, and early stage disease were independent predictors of a better outcome in multivariate analysis. The decade of treatment was an independent prognostic factor for cancer-specific mortality (hazard ratio, 0.42; 95% confidence interval, 0.3-0.6).
  
  
  CONCLUSIONS
  The survival rate of patients with OCSCC improved significantly during the past 2 decades despite older age, more advanced disease stage, and a higher rate of distant metastases. The current results suggest that the prognosis for patients with OCSCC has improved over time, presumably because of advances in imaging and therapy.
authors.affiliation: Department of Otolaryngology Rambam Medical Center and Faculty of Medicine, the Technion, Israel Institute of Technology, Haifa, Israel.
authors.forename: Moran
authors.initials: M
authors.lastname: Amit
authors.forename: Tzu-Chen
authors.initials: TC
authors.lastname: Yen
authors.forename: Chun-Ta
authors.initials: CT
authors.lastname: Liao
authors.forename: Pankaj
authors.initials: P
authors.lastname: Chaturvedi
authors.forename: Jai Prakash
authors.initials: JP
authors.lastname: Agarwal
authors.forename: Luiz P
authors.initials: LP
authors.lastname: Kowalski
authors.forename: Ardalan
authors.initials: A
authors.lastname: Ebrahimi
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Clark
authors.forename: Matthias
authors.initials: M
authors.lastname: Kreppel
authors.forename: Joachim
authors.initials: J
authors.lastname: Zöller
authors.forename: Eran
authors.initials: E
authors.lastname: Fridman
authors.forename: Villaret A
authors.initials: VA
authors.lastname: Bolzoni
authors.forename: Jatin P
authors.initials: JP
authors.lastname: Shah
authors.forename: Yoav
authors.initials: Y
authors.lastname: Binenbaum
authors.forename: Snehal G
authors.initials: SG
authors.lastname: Patel
authors.forename: Ziv
authors.initials: Z
authors.lastname: Gil
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D003299:Cooperative Behavior; D006258:Head and Neck Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D006801:Humans; D007391:International Cooperation; D008137:Longitudinal Studies; D008875:Middle Aged; D009055:Mouth / Q000000981:diagnostic imaging / Q000601:surgery; D009062:Mouth Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D017063:Outcome Assessment, Health Care; D011379:Prognosis; D011859:Radiography; D011877:Radionuclide Imaging; D018714:Radiotherapy, Adjuvant / Q000379:methods; D012189:Retrospective Studies; D000077195:Squamous Cell Carcinoma of Head and Neck; D055815:Young Adult
keywords: margins; oral cavity; squamous; survival; time; trends