To evaluate in a retrospective study the improvements in prostate cancer detection rates for patients with a prostate gland larger than 30 cm³ using a systematic 14-core biopsy strategy compared with a systematic 8-core biopsy.

We retrospectively assessed 273 patients with screened prostate-specific antigen (PSA) levels of 3.0 to 50.0 ng/mL. A total of 204 patients with a prostate volume of 30 cm³ or larger and with normal digital rectal examination findings were enrolled in this study. Of the 204 patients, 110 underwent 8-core biopsy and 94 underwent 14-core biopsy of the prostate. We compared the cancer detection rates of prostate biopsy between the 8 and 14-core groups using total PSA, free/total PSA ratio, PSA density, and PSA density adjusted by transition zone volume. We also analyzed the Gleason grade of the biopsy core and the radical prostatectomy specimens.

Of the 204 patients, 40 (19.5%) were identified as having prostate adenocarcinoma. The cancer detection rate for the 8 and 14-core groups was 14.5% (16 of 110 patients) and 24.5% (23 of 94 patients), respectively. The 14-core biopsy had a statistically significant greater cancer detection rate than did the 8-core group in patients with a prostate volume of 30 to 40 cm³ (36.7% versus 11.8%, respectively, P<0.05) and a PSA density adjusted by transition zone volume of 0.38 ng/mL/cm³ or greater (47.8% versus 20.0%, respectively, P <0.05). The difference in tumor grade between the 8 and 14-core biopsy samples was not statistically significant.

The 14-core prostate needle biopsy is a recommended method for detecting prostate cancer in a large-volume prostate gland without increasing the risk of complications.