The diagnostic accuracy of the age-adjusted and prostate volume-adjusted biopsy method in males with prostate specific antigen levels of 4.1-10.0 ng/mL

Background: The authors evaluated a new age-adjusted and prostate volume-adjusted biopsy method for the detection of prostate carcinoma through the transperineal and the transrectal approaches in men with PSA levels of 4.1-10.0 ng/mL.

Methods: The value of the adjusted biopsy method was calculated by using the following four factors: 1) life expectancy in Japanese men in 1998, 2) prostate volume estimated by transrectal ultrasonography, 3) tumor doubling time (4 years), and 4) tumor volume that influenced death (20 cc). The number of biopsy sites was set at 8-20. Between August, 1999 and December, 2001, 100 men age <or= 79 years with prostate specific antigen (PSA) levels of 4.1-10.0 ng/mL underwent age-adjusted and volume-adjusted, systematic prostate biopsy.

Results: The detection rate for the adjusted biopsy method was 46% (46 of 100 men). The clinical stage of prostate carcinoma was Stage II in 85% of patients and Stage III in 15% of patients. If routine six-sextant biopsy had been performed in all of the men who underwent adjusted systematic biopsy, then 15 of 46 patients (33%) with prostate carcinoma would have been missed. The detection rates of prostate carcinoma in men who underwent adjusted biopsies were relatively high, especially in men with PSA levels of 6.1-10.0 ng/mL, men age <or= 64 years, men with prostate volumes >or= 50 cc, and men with PSA density (PSAD) levels <or= 0.15 ng/mL/cc compared with the detection rates from six-sextant and directed biopsies. The high detection rates were observed from biopsy sites at the posterior aspect of the lateral lobe through both the transperineal approach and the transrectal approach and at the anterior aspect of the transition zone through the transperineal approach.

Conclusions: The age-adjusted and prostate volume-adjusted prostate biopsy method was more useful for detecting clinically significant disease compared with the traditional six-sextant biopsy method. This adjusted biopsy method was especially useful in patients age <or= 64 years, patients with large prostate volumes (>/= 50 cc), and patients with PSAD levels <or= 0.15 ng/mL/cc. The authors recommend that patients undergo an additional transition zone biopsy at the anterior aspect through the transperineal approach.