title: Colonoscopy effects on serum prostate specific antigen levels.
abstract: BACKGROUND
  To evaluate the colonoscopy effects on serum levels of prostate specific antigen (PSA) and PSA ratio.
  
  
  METHODS
  Thirty men were studied (median age 68 years, range 32-89). All of them had their serum PSA (total and free) measured 24 hours prior to colonoscopy and also 24 hours, 7 and 30 days after procedure.
  
  
  RESULTS
  14 of 30 (47%) patients, had significantly (p = 0.045) increased Total PSA levels 24 hours after the procedure, 14 (47%) patients had insignificantly (p = 0.139) increased levels 7 days after, while 13 (43%) of them had insignificantly (p = 0.061) increased levels 30 days after colonoscopy. In 7 patients (23%), with total PSA levels in the "gray zone" (4-10 ng/ml) before colonoscopy, a near significant (p = 0.063) raise in PSA ratio was also observed 24 hours after.
  
  
  CONCLUSIONS
  Flexible colonoscopy affect serum PSA (free and total) levels in certain patients. Special attention must be given to those patients with PSA levels in the "gray zone" before colonoscopy.
authors.affiliation: Department of Urology, University of Athens, Greece.
authors.forename: C
authors.initials: C
authors.lastname: Barbatzas
authors.forename: A
authors.initials: A
authors.lastname: Dellis
authors.forename: I
authors.initials: I
authors.lastname: Grivas
authors.forename: N
authors.initials: N
authors.lastname: Trakas
authors.forename: A
authors.initials: A
authors.lastname: Ekonomou
authors.forename: A
authors.initials: A
authors.lastname: Kostakopoulos
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003113:Colonoscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*
chemical_list: D017430:Prostate-Specific Antigen