title: The importance of actual tumor growth rate on disease free survival and overall survival in laryngeal squamous cell carcinoma.
abstract: OBJECTIVE
  Evaluation of the variation in tumor growth rate and the influence of tumor growth rate on disease free survival (DFS) and overall survival (OS) in laryngeal squamous cell carcinoma (LSCC).
  
  
  METHODS
  We delineated tumor volume on a diagnostic and planning CT scan in 131 patients with laryngeal squamous cell carcinoma and calculated the tumor growth rate. Primary endpoint was DFS. Follow up data were collected retrospectively.
  
  
  RESULTS
  A large variation in tumor growth rate was seen. When dichotomized with a cut-off point of -0.3 ln(cc/day), we found a significant association between high growth rate and worse DFS (p = 0.008) and OS (p = 0.013). After stepwise adjustment for potential confounders (age, differentiation and tumor volume) this significant association persisted. However, after adjustment of N-stage association disappeared. Exploratory analyses suggested a strong association between N-stage and tumor growth rate.
  
  
  CONCLUSIONS
  In laryngeal squamous cell carcinoma, there is a large variation in tumor growth rate. This tumor growth rate seems to be an important factor in disease free survival and OS. This tumor growth rate is independent of age, differentiation and tumor volume associated with DFS, but N-stage seems to be a more important risk factor.
authors.affiliation: University Medical Centre Utrecht, Department of Radiation Oncology, The Netherlands. Electronic address: l.w.vanbockel@umcutrecht.nl.
authors.forename: Liselotte W
authors.initials: LW
authors.lastname: van Bockel
authors.affiliation: Erasmus Medical Centre, Department of Radiation Oncology, Rotterdam, The Netherlands. Electronic address: g.verduijn@erasmusmc.nl.
authors.forename: Gerda M
authors.initials: GM
authors.lastname: Verduijn
authors.affiliation: University Medical Centre Utrecht, Julius Center for Health Sciences and Primary Care, The Netherlands. Electronic address: e.monninkhof@umcutrecht.nl.
authors.forename: Evelyn M
authors.initials: EM
authors.lastname: Monninkhof
authors.affiliation: University Medical Centre Utrecht, Department of Radiology, The Netherlands. Electronic address: f.a.pameijer@umcutrecht.nl.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Pameijer
authors.affiliation: University Medical Centre Utrecht, Department of Radiation Oncology, The Netherlands. Electronic address: c.h.j.terhaard@umcutrecht.nl.
authors.forename: Chris H J
authors.initials: CH
authors.lastname: Terhaard
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007822:Laryngeal Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
keywords: DFS; Doubling time; Growth rate; Laryngeal carcinoma; OS; Outcome