Clinical outcome of transrectal ultrasound-guided prostate biopsy, targeting eight cores, for detecting prostate cancer in Japanese men.

Abstract

The objective of this study was to evaluate the clinical usefulness of transrectal ultrasound (TRUS)-guided eight-core prostate biopsy for detecting prostate cancer in Japanese men. Between January 1998 and September 2002, a total of 628 consecutive patients underwent TRUS-guided biopsy of the prostate. As a rule, eight cores were taken from each patient; that is, standard sextant cores from the peripheral zone and two additional cores from the bilateral anterior lateral horns (ALHs). The present study included 428 patients who underwent an initial biopsy, whose age was between 50 and 79 years, and whose prostate-specific antigen (PSA) value was less than 20.0 ng/ml. The cancer detection rate was calculated according to age, PSA, digital rectal examination (DRE) and TRUS findings, prostate volume, and PSA density (PSAD). We also assessed whether the sampling of the two extra cores from the ALHs increased the cancer detection rate. Of the 428 patients, 101 (23.6%) were diagnosed as having cancer by eight-core prostate biopsies. The cancer detection rate was significantly associated with the PSA value (ng/ml; < or =4 versus 4-10, versus 10-20), DRE findings (normal versus abnormal), TRUS findings (normal versus abnormal), and PSAD (ng/ml2; < or =0.15 versus >0.15). but not with age (years: < or =70 versus >70) on prostate volume (ml; < or =30 versus 30-50, versus >50). Of the 101 patients diagnosed as having prostate cancer, 11 had positive cores only in the ALH; that is, the increase in the cancer detection rate yielded by obtaining two extra cores from the ALHs was 10.9%. Despite the reasonable strategy, systematic prostate biopsy targeting eight cores did not significantly improve the cancer detection rate compared with that of standard sextant biopsy in Japanese men. However, the increased cancer detection rate yielded by additional sampling from the ALHs was comparatively prominent in the subgroup whose PSA value was in the gray zone (4-10 ng/ml) or whose prostate volume was greater than 50 ml.