[Clinical usefulness of free PSA/total PSA ratio in the early diagnosis of prostatic cancer].
OBJECTIVE
To determine the clinical utility of free/total PSA ratio and PSA density in the early diagnosis of prostate cancer (patients with serum PSA between 4 and 10 ng/ml) and to determine the differences, if any, in the free/total PSA ratio in patients with cancer and those with benign prostatic hyperplasia (BPH).


METHODS
A prospective and descriptive study was conducted on 61 patients with low grade obstructive symptoms and total serum PSA between 4 and 10 ng/ml (group 1), and 42 patients who underwent prostate surgery and had an anatomopathologically confirmed diagnosis of BPH (group 2). Free and total PSA were determined, as well as prostate volume by transrectal US, in all cases. Prostate biopsy was performed in all patients with a total PSA value between 4-10 ng/ml. The sensitivity, specificity, positive and negative prognostic values of free/total PSA ratio and PSA density were analyzed.


RESULTS
The mean age of the patients in group 1 was 67.7 years and 68.3 years in group 2. The mean prostate volume by US was 55.2 and 47.1, respectively (n.s.). The mean total PSA was 6.39 ng/ml for group 1 and 5.73 ng/ml for group 2 (n.s.). No significant difference was found between the mean free PSA values of both groups. However, the free/total PSA ratio and PSA density were significantly different (p < 0.000). In group 1 (total PSA 4-10 ng/ml), prostate biopsy was positive in 32.8% of the patients. In this group of patients, there were no significant differences in the parameters analyzed. Application of different cutoffs for both tests showed a higher clinical utility for the 0.24-0.30 range.


CONCLUSIONS
At similar mean prostate volume and mean total PSA, significant differences were found in the free/total PSA ratio and PSA density of patients submitted to surgery for BPH and those with a total PSA value of 4-10 ng/ml. However, these results were not observed when patients with PSA of 4-10 ng/ml were analyzed for presence or absence of evidence of malignancy in the prostate biopsy.
Laguna Pes
M P
MP
Servicio de Urología, Hospital General La Mancha-Centro, Alcázar de San Juan, Ciudad Real, España.
Guinda Sevillano
C
C
Zazo Romojaro
A
A
Domínguez
J
J
García Luzón
A
A
Borrego Hernando
J
J
Gimeno Collado
A
A
D000368:Aged; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D013997:Time Factors
D017430:Prostate-Specific Antigen