title: Biochemical and clinical significance of the posttreatment prostate-specific antigen bounce for prostate cancer patients treated with external beam radiation therapy alone: a multiinstitutional pooled analysis.
abstract: BACKGROUND
  The posttreatment prostate-specific antigen (PSA) bounce phenomenon has been recognized in at least 20% of all patients treated with radiation. The purpose of the current report was to determine if there was a difference in biochemical and clinical control between the bounce and nonbounce (NB) patients using pooled data on 4839 patients with T1-2 prostate cancer treated with external beam radiation therapy (RT) alone at 9 institutions between 1986 and 1995.
  
  
  METHODS
  The median follow-up was 6.3 years. A posttreatment PSA bounce was defined by a minimal rise of 0.4 ng/mL over a 6-month follow-up period, followed by a drop in PSA level of any magnitude. Endpoints included no biochemical evidence of disease (bNED) failure (BF) (ASTRO definition), distant failure (DF), cause-specific failure (CSF), and overall survival (OS). Patients were stratified by pretreatment PSA, Gleason score, T stage, age, dose, and risk group.
  
  
  RESULTS
  In all, 978 (20%) patients experienced at least 1 posttreatment PSA bounce. Within 3 subgroups (risk group, pretreatment PSA, and age), statistically significant differences of remaining bounce-free were observed on univariate analysis. Patients < 70 years had a 72% chance of remaining bounce-free at 5 years compared with 75% for older patients (P = .04). The NB patients had 72% bNED control at 10 years compared with 58% for the bounce patients. The effect of a bounce remained statistically significant on multivariate analysis (P < .0001). No statistically significant difference in DF, CSF, or OS was observed.
  
  
  CONCLUSIONS
  Patients treated with external beam radiation therapy alone who experience a posttreatment PSA bounce have increased risk of BF. However, this did not translate into a difference in clinical failure with the available follow-up in the current study.
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA. eric.horwitz@fccc.edu
authors.forename: Eric M
authors.initials: EM
authors.lastname: Horwitz
authors.forename: Lawrence B
authors.initials: LB
authors.lastname: Levy
authors.forename: Howard D
authors.initials: HD
authors.lastname: Thames
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Kupelian
authors.forename: Alvaro A
authors.initials: AA
authors.lastname: Martinez
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Michalski
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Pisansky
authors.forename: Howard M
authors.initials: HM
authors.lastname: Sandler
authors.forename: William U
authors.initials: WU
authors.lastname: Shipley
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zelefsky
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Zietman
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Kuban
mesh_terms: D000328:Adult; D000368:Aged; D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000532:radiotherapy*; D012306:Risk; D017211:Treatment Failure
chemical_list: D017430:Prostate-Specific Antigen