Objectives: We compared the cancer detection rate of extended 14-core biopsy with that of sextant biopsy to assess whether additional biopsy cores are useful for detection of prostate cancer and to clarify the indications for obtaining additional cores.
Methods: Study subjects were 313 patients who underwent transrectal ultrasound-guided 14-core biopsy because of a prostate-specific antigen (PSA) level greater than 4.0 ng/mL and/or abnormalities found on digital rectal examination (DRE). In addition to the standard 6 biopsy cores, 6 lateral cores were obtained as well as 2 transition zone cores. PSA density (PSAD) was determined as the total PSA level divided by the prostate volume as estimated by transrectal ultrasound.
Results: Prostate cancer was diagnosed in 127 patients (40.6%). In 28 (22%) patients, the cancer would not have been detected by the sextant method alone. Among 211 patients with normal DRE findings, the cancer detection rate with 14-core biopsy was statistically higher than that with 6-core biopsy in the 141 patients with a PSA level of 4.01 ng/mL to 10.0 ng/mL, and 14 (38.9%) of 36 cancers were diagnosed in additional cores only, not in the standard sextant biopsy cores. Among the 141 patients with a gray-zone PSA level, the cancer detection rate with extended biopsy was statistically higher in those with PSAD greater than 0.13 ng/mL.
Conclusions: Lateral biopsy should be used in conjunction with sextant biopsy in patients with a PSA level of 4.01 ng/mL to 10.0 ng/mL with normal DRE findings, especially in those with PSAD greater than 0.13 ng/mL.