Differences in tumor core distribution between palpable and nonpalpable prostate tumors in patients diagnosed using extensive transperineal ultrasound-guided template prostate biopsy.

BACKGROUND: The authors performed extensive transperineal ultrasound-guided template prostate biopsies to investigate carcinoma core distribution. METHODS: Between August 2000 and May 2004, 371 men underwent template biopsies. Three hundred twelve patients had not undergone a previous biopsy (first group) and 59 had undergone previous transrectal sextant biopsies (repeat group). Of the 312 patients in the first group, 236 had normal digital rectal examination (DRE) findings (DRE- first group) and 76 patients had an abnormal DRE (DRE+ first group). A mean of 20.1 biopsy cores (range, 9-38 cores) was taken from the entire prostate. The region > 2.0 cm from the rectal face of the prostate was defined as the anterior region and the remaining area was defined as the posterior region. RESULTS: In the DRE- first group, the carcinoma core rate (number of tumor cores/number of biopsy cores) in the anterior region (7.2%) did not differ from that of the posterior region (7.3%) (P = 0.9635). However, in the DRE+ first group, the carcinoma core rate in the posterior region (22.0%) was found to be higher than in the anterior region (13.2%) (P < 0.0001). In the repeat group, the carcinoma core rate in the posterior region (3.1%) was significantly (P = 0.0008) lower than that exhibited in the anterior region (7.2%). CONCLUSIONS: The results of the current study suggest that nonpalpable prostate carcinoma is distributed equally within the entire prostate, although palpable carcinoma is distributed mainly in the posterior region and many of the tumor foci in the anterior region may be missed by a transrectal sextant biopsy. The examination of radical prostatectomy specimens is required to prove these results.

Difference of cancer core distribution between first and repeat biopsy: In patients diagnosed by extensive transperineal ultrasound guided template prostate biopsy.

BACKGROUND: We performed extensive transperineal ultrasound guided template prostate biopsy and evaluated cancer core distribution. METHODS: From August 2000 to May 2002, 113 men with prostate specific antigen levels between 4.0 and 10.0 ng/ml underwent template biopsy. Eighty-six had no previous biopsy (first group) and 27 had previous transrectal sextant biopsies (repeat group). A mean of 18.4 biopsy cores were taken. We defined the region over 2 cm from the rectal face of the prostate as the anterior region and the other as the posterior. RESULTS: Cancer was detected in 49 of 113 (43%) men. Forty-two were in the first group and seven in the repeat group. In the first group, the cancer core rate (cancer core number/biopsy core number) in the anterior region (7.0%) had no difference from that in the posterior region (8.6%) (P = 0.7111). But in the repeat group, the cancer core rate in the anterior region (4.6%) was higher than in the posterior (1.5%) (P < 0.0001). CONCLUSIONS: These results suggest that transrectal sextant biopsies miss more cancers in the anterior region than in the posterior. We believe template technique has an advantage to be able to detect cancer equally in the anterior and posterior.