Free to total PSA ratio is not a reliable predictor of prostate biopsy outcome.
OBJECTIVE
The aim of this study was to assess the validity of predictors of prostate biopsy outcome in order to improve their positive predictive value.


METHODS
The study material consisted of a consecutive series of 410 prostate biopsies performed during 2003. The variables tested as possible predictors were age, findings at palpation (DRE) and ultrasonography (TRUS), total prostate-specific antigen (PSA), and free-to-total prostate-specific antigen (F/T) ratio. The association with biopsy outcome (cancer vs non-cancer) was investigated by univariate and multivariate analysis.


RESULTS
All tested variables showed a statistically significant and independent association with biopsy outcome both in univariate and multivariate analysis. Nevertheless, no variable had good performance as a biopsy indicator: depending on the considered variable, three to nine cancer biopsies would be delayed in order to avoid ten benign biopsies. Using 0.12, 0.15 and 0.20 as the cutoff for F/T would avoid 77.3%, 64.4% and 43.1% of benign biopsies but would delay 54.0%, 35.6% and 21.0% of cancer biopsies, respectively.


CONCLUSIONS
Although it may contribute to diagnostic suspicion, F/T should never exclude a biopsy indicated because of suspicion arising from other diagnostic tests.
Centro per lo Studio e la Prevenzione Oncologica, Florence, Italy. s.ciatto@cspo.it
Stefano
S
Ciatto
Tiziana
T
Rubeca
Massimo
M
Confortini
Giovanni
G
Pontenani
Claudio
C
Lombardi
Paola
P
Zendron
Simonetta
S
Di Lollo
Emanuele
E
Crocetti
D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000276:immunology* / Q000473:pathology*; D015203:Reproducibility of Results
D017430:Prostate-Specific Antigen