title: Observations of pretreatment prostate-specific antigen doubling time in 107 patients referred for definitive radiotherapy.
abstract: OBJECTIVE
  To determine pretreatment prostate-specific antigen doubling times (PSADT) in patients referred for definitive radiotherapy.
  
  
  METHODS
  One hundred and seven patients with histologically proven nonmetastatic prostate cancer and an elevated prostate-specific antigen (PSA) who were referred for radiation therapy had three serum PSA values obtained prior to the start of definitive therapy. Prostate-specific antigen doubling times were calculated by linear regression.
  
  
  RESULTS
  Prostate-specific antigen values increased during the period of observation in 78 patients (73%). Forty-three patients (40%) had calculated PSADT of less than 2 years and of those patients with pretreatment serum PSA values of greater than 10 ng/mL more than 50% has calculated PSADT of less than 2 years.
  
  
  CONCLUSIONS
  A significant minority of patients referred for radiotherapy have calculated PSADT of less than 2 years. The significance of this relatively fast growth rate is as yet undetermined, but suggests that patients referred for radiotherapy may have aggressive disease prior to treatment.
authors.affiliation: Fox Chase Cancer Center, Department of Radiation Oncology, Philadelphia, PA 19177.
authors.forename: W R
authors.initials: WR
authors.lastname: Lee
authors.forename: G E
authors.initials: GE
authors.lastname: Hanks
authors.forename: B W
authors.initials: BW
authors.lastname: Corn
authors.forename: T E
authors.initials: TE
authors.lastname: Schultheiss
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology* / Q000473:pathology / Q000532:radiotherapy; D000368:Aged; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000276:immunology* / Q000473:pathology / Q000532:radiotherapy; D013997:Time Factors
chemical_list: D017430:Prostate-Specific Antigen