title: Normalization of prostate specific antigen in patients treated with intensity modulated radiotherapy for clinically localized prostate cancer.
abstract: BACKGROUND
  The purpose of this study was to determine the expected time to prostate specific antigen (PSA) normalization with or without neoadjuvant androgen deprivation (NAAD) therapy after treatment with intensity modulated radiotherapy (IMRT) for patients with clinically localized prostate cancer.
  
  
  METHODS
  A retrospective cohort research design was used. A total of 133 patients with clinical stage T1c to T3b prostate cancer (2002 AJCC staging) treated in a community setting between January 2002 and July 2005 were reviewed for time to PSA normalization using 1 ng/mL and 2 ng/mL as criteria. All patients received IMRT as part of their management. Times to PSA normalization were calculated using the Kaplan-Meier method. Significance was assessed at p < 0.05.
  
  
  RESULTS
  Fifty-six of the 133 patients received NAAD (42.1%). Thirty-one patients (23.8%) received radiation to a limited pelvic field followed by an IMRT boost, while 99 patients received IMRT alone (76.2%). The times to serum PSA normalization < 2 ng/mL when treated with or without NAAD were 298 ± 24 and 302 ± 33 days (mean ± SEM), respectively (p > 0.05), and 303 ± 24 and 405 ± 46 days, respectively, for PSA < 1 ng/mL (p < 0.05). Stage T1 and T2 tumors had significantly increased time to PSA normalization < 1 ng/mL in comparison to Stage T3 tumors. Also, higher Gleason scores were significantly correlated with a faster time to PSA normalization < 1 ng/mL.
  
  
  CONCLUSIONS
  Use of NAAD in conjunction with IMRT leads to a significantly shortened time to normalization of serum PSA < 1 ng/mL in patients with clinically localized prostate cancer.
authors.affiliation: College of Human Medicine, Michigan State University, East Lansing, MI, USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Schmitz
authors.forename: Gilbert D A
authors.initials: GD
authors.lastname: Padula
authors.forename: Patrick Y
authors.initials: PY
authors.lastname: Chun
authors.forename: Alan T
authors.initials: AT
authors.lastname: Davis
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000097:blood / Q000528:radiation effects; D015331:Cohort Studies; D003131:Combined Modality Therapy; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D017430:Prostate-Specific Antigen / Q000097:blood* / Q000528:radiation effects; D011471:Prostatic Neoplasms / Q000097:blood* / Q000473:pathology / Q000532:radiotherapy*; D050397:Radiotherapy, Intensity-Modulated; D012189:Retrospective Studies
chemical_list: D000726:Androgen Antagonists; D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen