Additional sampling of dorsal apex on systematic prostate biopsy: impact on early detection of prostate cancer.

OBJECTIVES

To evaluate the significance of additional routine biopsies targeting the dorsal apex (DA) in men undergoing transrectal ultrasound (TRUS)-guided biopsies.

METHODS

This study included 429 patients undergoing TRUS-guided biopsy of the prostate. As a rule, 12 cores were taken from each patient, with 8 cores taken from the peripheral zones, 2 cores from the transition zones, and 2 additional cores from the DA.

RESULTS

Cancer was detected in 150 patients, of whom 97 had positive cores in the DA. Furthermore, cancer was detected only in the DA in 14 patients; that is, the increase in the cancer detection rate by additional sampling from the DA was 9.3%. Significant differences were found in the prostate-specific antigen level, prostate-specific antigen density, digital rectal examination findings, TRUS findings, clinical T stage, and percentage of positive biopsy cores among the 14 men with positive cores in the DA alone (group 1), 83 in the DA and other regions (group 2), and 53 in regions except for the DA (group 3). Of these, radical prostatectomy was performed in 6, 41, and 26 in groups 1, 2, and 3, respectively. No significant differences were found in the several pathologic factors among these groups, and 5 of the 6 patients in group 1 had a tumor volume greater than 0.5 cm3.

CONCLUSIONS

Additional sampling of biopsy cores from the DA significantly improved the cancer detection rate, particularly for early disease; however, this method does not appear to increase the detection of insignificant cancer. Accordingly, we recommend performing systematic biopsy routinely targeting the DA.