Do changes in a high serum prostate-specific antigen level and the free/total prostate-specific antigen ratio after antibiotic treatment rule out biopsy and the suspicion of cancer?
OBJECTIVE
To evaluate the impact of antibiotic treatment in patients with higher-than-normal prostate-specific antigen (PSA) levels in terms of changes both in total PSA and free/total (f/t) PSA ratios.


METHODS
Serum PSA and f/t PSA changes after antibiotic treatment in 85 patients with normal digital rectal examination but elevated age-adjusted serum PSA levels were evaluated with relevance to biopsy results.


RESULTS
Serum PSA levels decreased after antibiotic treatment in 47 of 85 patients. The f/t PSA ratio decreased or remained unchanged in 21 and increased in 26 of these 47 cases. Cancer detection rate in the former group was 52.4% (11/21), while it was 7.7% (2/26) in the latter (p = 0.002). There were 38 patients with increased PSA levels after antibiotics. The f/t PSA ratios decreased or remained unchanged in 20 and increased in 18 of these 38 cases. Cancer detection rates were 55% (11/20) in the former and 16.7% (3/18) in the latter group (p = 0.003).


CONCLUSIONS
The PSA and f/t PSA levels may change with long-term antibiotic treatment in patients with elevated PSA values. The f/t PSA ratio rather than total PSA appears to be more helpful in suggesting prostate cancer in these cases.
Dirim
Ayhan
A
Department of Urology, Baskent University School of Medicine, Ankara, Turkey. drayhan_dirim@yahoo.com
Tekin
Mehmet Ilteris
MI
Koyluoglu
Eser
E
Oguzulgen
Ahmet Ibrahim
AI
Peskircioglu
Levent
L
Ozkardes
Hakan
H
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001707:Biopsy, Needle; D002908:Chronic Disease; D051517:Digital Rectal Examination; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D011472:Prostatitis / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D015854:Up-Regulation
D000900:Anti-Bacterial Agents; D017430:Prostate-Specific Antigen