Using multiple cutpoints for the free-to-total prostate specific antigen ratio improves the accuracy of prostate cancer detection.
BACKGROUND
Using a single cutpoint for the free-to-total (F/T) prostate specific antigen (PSA) ratio loses important diagnostic information. We evaluated the performance of multiple F/T PSA cutpoints in detecting prostate cancer in men with nonspecific PSA values.


METHODS
We extracted sensitivity and specificity data from 12 studies reporting on >or=30 cancer patients with PSA values between 2.0 and 10.0 ng/mL. We calculated stratum-specific likelihood ratios (LR) and areas under the receiver operating characteristic (ROC) curves.


RESULTS
Multiple cutpoints for the F/T PSA ratio significantly increased the area under the ROC (0.70) compared with the single investigator-selected cutpoint (0.62), P < 0.004. The LR for the most positive cutpoint stratum (2.62) was significantly higher than the LR for a positive test from the single cutpoint (1.36), P < 0.004.


CONCLUSIONS
Using multiple cutpoints increased the discriminating power of the F/T PSA ratio and led to greater probability revisions in the most positive test-result strata.
Department of Medicine, Albuquerque VA Medical Center, Albuquerque, New Mexico 87108, USA. rhoffman@unm.edu
Richard M
RM
Hoffman
David L
DL
Clanon
Margarita
M
Chavez
John C
JC
Peirce
D014408:Biomarkers, Tumor / Q000097:blood*; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D012372:ROC Curve
D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen