[The diagnostic effectiveness of repeat echo-guided transrectal biopsy as a function of the clinical and...

To evaluate the incidence of false negatives in our series of ultrasound-guided prostate biopsies.

106 patients (79% with high PSA and the remainder with suspicion digital rectal examination) with cancer-free transrectal biopsy underwent at least a second biopsy limited to the peripheral area: mean age 68 +/- 6.4 years, mean number of biopsy punctures 5 +/- 1, 95% patients with biopsies from both lobes. Re-biopsy indication was the result of persistently high PSA in 84 patients (13 with glandular atypia and 3 with PIN 3), or suspicion digital rectal examination in 22 patients (4 with glandular atypia and 2 with PIN 3). Second biopsy was performed in 89% patients, third in 10% and fourth in just one patient.

14% patients were found to have cancer, tumour diagnosis being made on the second biopsy in 93.3% cases. In patients with suspicion digital rectal examination only, cancer was detected in 31%, and 7.3% patients with high PSA had cancer; 40% patients with PIN 3 and 18% patients with glandular atypia had cancer. In patients with high PSA only, PSA (p = 0.6) and PSAD (p = 0.3) levels and the presence of changes in the ultrasound (p = 0.8) were not enough to detect cancer patients. Deobstructive prostate surgery was performed in 15 patients after re-biopsy, cancer being found in the transitional area in 20% cases.

Our recommendation is that all patients with suspicion digital rectal examination, high grade PIN or glandular atypia should undergo re-biopsy which should include the transitional area. Due to the low incidence of cancer in patients with persistently high PSA and the inefficiency of biochemical and ultrasound parameters to detect patients with cancer, we suggest that each case should be assessed on an individual basis.