Is transition zone biopsy valuable in benign prostatic hyperplasia patients with serum prostate-specific antigen >10 ng/ml and prior negative peripheral zone biopsy?

Objectives. To evaluate the importance of transition zone (TZ) biopsy in benign prostatic hyperplasia (BPH) patients with serum prostate-specific antigen (PSA) >10 ng/ml and prior negative peripheral zone (PZ) biopsy and to estimate the sensitivity of TZ biopsy. Material and methods. A total of 273 BPH patients with PSA >10 ng/ml and prior negative PZ biopsy underwent an extended biopsy protocol. In patients with a TZ volume <25 cm(3), four TZ biopsies were taken (two cores per side from the apex and base). In patients with a TZ volume >= 25 cm(3) (n = 183), six TZ biopsies were taken (three cores per side from the apex, middle and base). Overall, 215 patients were subjected to either transurethral resection of the prostate (n = 162) or open enucleation of the adenoma (n = 53). Results. The extended biopsy revealed prostate cancers in 21.2% of cases (58/273). The zonal distribution of the positive cores was as follow: PZ cancers only in 67.2% of cases (39/58), TZ cancers only in 13.8% (8/58) and PZ+TZ cancers in 19% (11/58). Overall, 73.6% (14/19) and 36.8% (7/19) of TZ cancers were detected at the apex and middle of the TZ, respectively, while no TZ cancers at all were detected at the base (p = 0.00015). The incidence of carcinoma on definitive pathology was 5.6% (12/215). Consequently, TZ biopsy detected only 61.3% (19/31) of TZ cancers. The incidence of pure TZ cancers was 7.3%. On the chi(2) test, patient age, serum PSA, transrectal ultrasonography findings and PSA density did not correlate. significantly with the detection rate of TZ cancer. Prostate volume (p = 0.023), TZ volume (p = 0.027) and PSA/TZ density (p = 0.007) were predictive of TZ cancers. Conclusions. Although TZ biopsy was the sole site of cancer in only 2.9% of cases (8/273), it improved the cancer detection rate by 14% in this selected group of patients. The majority (74%) of TZ cancers were detected at the apex site. TZ biopsy has a low sensitivity (61%).