title: Clinical impact of prolonged diagnosis to treatment interval (DTI) among patients with oropharyngeal squamous cell carcinoma.
abstract: OBJECTIVE
  We examined practice patterns using the National Cancer Data Base (NCDB) to determine risk factors for prolonged diagnosis to treatment interval (DTI) and survival outcomes in patients receiving chemoradiation for oropharyngeal squamous cell carcinoma (OPSCC).
  
  
  METHODS
  We identified 6606 NCDB patients with Stage III-IV OPSCC receiving chemoradiation from 2003 to 2006. We determined risk factors for prolonged DTI (>30days) using univariate and multivariable logistic regression models. We examined overall survival (OS) using Kaplan Meier and multivariable Cox proportional hazards models.
  
  
  RESULTS
  3586 (54.3%) patients had prolonged DTI. Race, IMRT, insurance status, and high volume facilities were significant risk factors for prolonged DTI. Patients with prolonged DTI had inferior OS compared to DTI⩽30days (Hazard Ratio (HR)=1.12, 95% CI 1.04-1.20, p=0.005). For every week increase in DTI there was a 2.2% (95% CI 1.1-3.3%, p<0.001) increase in risk of death. Patients receiving IMRT, treatment at academic, or high-volume facilities were more likely to experience prolonged DTI (High vs. Low volume: 61.5% vs. 51.8%, adjusted OR 1.38, 95% CI 1.21-1.58; Academic vs. Community: 59.5% vs. 50.6%, adjusted OR 1.26, 95% CI 1.13-1.42; non-IMRT vs. IMRT: 53.4% vs. 56.5%; adjusted OR 1.17, 95% CI 1.04-1.31).
  
  
  CONCLUSIONS
  Our results suggest that prolonged DTI has a significant impact on survival outcomes. We observed disparities in DTI by socioeconomic factors. However, facility level factors such as academic affiliation, high volume, and IMRT also increased risk of DTI. These findings should be considered in developing efficient pathways to mitigate adverse effects of prolonged DTI.
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, United States. Electronic address: sonam.sharma@uphs.upenn.edu.
authors.forename: Sonam
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, United States.
authors.forename: Justin
authors.initials: J
authors.lastname: Bekelman
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, United States.
authors.forename: Alexander
authors.initials: A
authors.lastname: Lin
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, United States.
authors.forename: J Nicholas
authors.initials: JN
authors.lastname: Lukens
authors.affiliation: Memorial Sloan Kettering Cancer Center Department of Surgery, Head & Neck Service, United States.
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Roman
authors.affiliation: Department of Biostatistics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania, United States.
authors.forename: Nandita
authors.initials: N
authors.lastname: Mitra
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, United States.
authors.forename: Samuel
authors.initials: S
authors.lastname: Swisher-McClure
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009959:Oropharyngeal Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy*; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D013996:Time and Motion Studies
keywords: National Cancer Data Base; Oropharyngeal cancer; Treatment delays