title: Outcome of local failures after oral cancer - recurrence vs. second primary.
abstract: OBJECTIVE
  A high risk of new mucosal malignancies of the upper aerodigestive tract (UADT) is seen in patients successfully treated for oral cancer. The prognosis is unclear for these patients. A typical failure may be located at the site of the first tumor i.e. a local recurrence; or separately as a second primary tumor (SPT). It is unknown whether these two types of local failures have different prognosis.
  
  
  METHODS
  Longitudinal observational cohort study employing prospectively collected data over 25 years.
  
  
  METHODS
  The rate of local recurrences and UADT SPTs was analyzed in 151 patients previously treated for T1N0M0 oral squamous cell carcinoma. Survival after failure was compared between patients with local recurrence and local SPT.
  
  
  RESULTS
  All patients had a 5-year cancer specific survival of 86.3%. Of the 151 patients, 20 had a local recurrence, and 16 had an UADT SPT. After a local failure, survival was median 17.2 months for local recurrence and 18.9 for UADT SPT (cancer specific). Time from primary tumor treatment to local recurrence was median 42 and months vs. 125 months for UADT SPTs. A similar linear pattern of presentation over time was seen for both tumor types.
  
  
  CONCLUSIONS
  Outcome was poor after the date of the local failure. No difference in survival was seen whether the failure was a local recurrence or a second primary tumor. The similarity in survival and pattern of presentation suggests that these two entities may be biologically analogous.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Oslo University Hospital, Oslo, Norway. erlre@online.no
authors.forename: Erlend
authors.initials: E
authors.lastname: Rennemo
authors.forename: Ulf
authors.initials: U
authors.lastname: Zätterström
authors.forename: Morten
authors.initials: M
authors.lastname: Boysen
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D016009:Chi-Square Distribution; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007822:Laryngeal Neoplasms / Q000401:mortality; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D009364:Neoplasm Recurrence, Local / Q000401:mortality*; D009367:Neoplasm Staging; D016609:Neoplasms, Second Primary / Q000401:mortality*; D010610:Pharyngeal Neoplasms / Q000401:mortality; D011379:Prognosis; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D017211:Treatment Failure