title: The impact of increasing dose on overall survival in prostate cancer.
abstract: OBJECTIVE
  To assess the impact of increasing dose on overall survival (OS) for prostate cancer patients.
  
  
  METHODS
  Treatment data were obtained on more than 20,000 patients in the National Oncology Data Alliance®, a proprietary database of merged tumor registries, who were treated for prostate cancer with definitive radiotherapy between 1995 and 2006. Eligible patients had complete data on total dose, T stage, use and timing of androgen deprivation therapy (ADT), and treatment start date (n = 20,028). Patients with prior malignancies were excluded.
  
  
  RESULTS
  On multivariate analysis, dose, T stage, grade, marital status, age, and neoadjuvant ADT were significant predictors of OS. Hazard ratios for OS declined monotonically with increasing dose, reaching 0.63 (95 % Confidence Interval 0.53-0.76) at ≥80 Gy. On subset analysis, neoadjuvant ADT significantly improved OS in high risk patients but was not significant in lower risk patients. The dose response was maintained across all risk groups. Medical comorbidities were balanced across all dose strata and sensitivity analysis demonstrated that other prognostic factors were unlikely to explain the observed dose response.
  
  
  CONCLUSIONS
  This study suggests that increasing dose significantly improves OS in prostate cancer patients treated with radiotherapy.
authors.affiliation: Department of Radiation Oncology, City of Hope National Medical Center, 1500 East Duarte Road, Duarte, CA, 91010, USA. mhall@coh.org.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Hall
authors.affiliation: Department of Radiation Oncology, City of Hope National Medical Center, 1500 East Duarte Road, Duarte, CA, 91010, USA. schultheiss@coh.org.
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Schultheiss
authors.affiliation: Division of Biostatistics, City of Hope National Medical Center, 1500 East Duarte Road, Duarte, CA, 91010, USA. dsmith02@coh.org.
authors.forename: David D
authors.initials: DD
authors.lastname: Smith
authors.affiliation: Department of Radiation Oncology, City of Hope National Medical Center, 1500 East Duarte Road, Duarte, CA, 91010, USA. bptseng@gmail.com.|Duke University Medical Center, Durham, NC, 27710, USA. bptseng@gmail.com.
authors.forename: Bertrand P
authors.initials: BP
authors.lastname: Tseng
authors.affiliation: Department of Radiation Oncology, City of Hope National Medical Center, 1500 East Duarte Road, Duarte, CA, 91010, USA. jwong@coh.org.
authors.forename: Jeffrey Y C
authors.initials: JY
authors.lastname: Wong
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use*; D059248:Chemoradiotherapy / Q000401:mortality*; D006801:Humans; D008297:Male; D020360:Neoadjuvant Therapy / Q000401:mortality*; D009367:Neoplasm Staging; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000401:mortality* / Q000628:therapy; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D015996:Survival Rate
chemical_list: D000726:Androgen Antagonists