title: Factors contributing to recurrence of oral cavity and laryngeal tumors and estimation of tumor age.
abstract: OBJECTIVE
  To identify factors contributing to local tumor recurrence in oral cavity and laryngeal squamous cell carcinomas treated with surgery alone, to approximate tumor age from time to recurrence data by applying Collins' law, and to identify factors that may affect time to recurrence.
  
  
  METHODS
  Retrospective review.
  
  
  METHODS
  A retrospective review of all patients treated for head and neck cancer from 1997 to 2013 at the University of Pittsburgh Medical Center was performed.
  
  
  RESULTS
  A total of 517 patients treated with surgery alone qualified for the study, of which 84 had local recurrence, and 433 had no local recurrences. History of tobacco use (P = .017), pack-year cigarette history (P = .001), and T stage (P = .03) were associated with disease recurrence. Overall, never tobacco users, those with fewer pack-years of smoking history, and those with lower T stage were more likely to recur. Time to recurrence was significantly shorter for laryngeal tumors compared to oral cavity tumors (P = .027). Median time to recurrence for oral cavity tumors was 8.6 months and laryngeal tumors was 7.1 months.
  
  
  CONCLUSIONS
  In this study, lower pack-year smoking history, lower T stage, and history of never tobacco use were associated with local tumor recurrence. Applying the concept of Collins' law to estimate the age of tumors at diagnosis, the median tumor age at diagnosis was estimated to be 8.6 months for oral cavity tumors and 7.1 months for laryngeal tumors.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, U.S.A.
authors.forename: Garret W
authors.initials: GW
authors.lastname: Choby
authors.forename: William G
authors.initials: WG
authors.lastname: Albergotti
authors.forename: James K
authors.initials: JK
authors.lastname: Byrd
authors.forename: Ann Marie
authors.initials: AM
authors.lastname: Egloff
authors.forename: Jonas T
authors.initials: JT
authors.lastname: Johnson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007822:Laryngeal Neoplasms / Q000175:diagnosis* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000601:surgery; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000209:etiology*; D009367:Neoplasm Staging; D013517:Otorhinolaryngologic Surgical Procedures; D010414:Pennsylvania / Q000453:epidemiology; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D055815:Young Adult
keywords: Collins' law; Head and neck cancer; local recurrence; risk of recurrence; squamous cell carcinoma; time to recurrence; tumor age