Increased detection of clinically significant prostate cancer by additional sampling from the anterior lateral horns of the peripheral zone in combination with the standard sextant biopsy.

BACKGROUND

The objective of the present study was to investigate whether obtaining an increased number of biopsy cores by sampling additional areas, along with the standard sextant biopsy, results in a higher rate of detection of potentially insignificant prostate cancer.

METHODS

We included 130 patients who underwent radical retropubic prostatectomy at our institution between January 1999 and June 2003 after being diagnosed as having prostate cancer based on systematic prostate biopsies that included the areas examined by standard sextant biopsies and the bilateral anterior lateral horns (ALHs) of the peripheral zone (PZ). Several clinicopathological factors were analyzed, focusing on the significance of additional sampling from ALHs in relation to the incidence of potentially insignificant cancer, which was defined as organ confined disease with tumor volume less than 0.5 cc and Gleason scores <7.

RESULTS

According to the location of positive biopsy results, these 130 patients were divided into three groups as follows: 61 patients (46.9%) with cancer detected from the cores taken by standard sextant biopsy only (group A), 15 (11.6%) from ALHs of the PZ only (group B), and 54 (41.5%) from both sites (group C). There were no significant differences in age, incidence of abnormal digital rectal examination, prostate volume, or biopsy Gleason score among these three groups; however, pretreatment serum PSA value in group C was significantly higher than that in groups A or B. Pathological examinations of radical prostatectomy specimens demonstrated that there were no significant differences in the incidence of lymphatic invasion, vascular invasion and perineural invasion, or Gleason score among the three groups; however, group C had a significantly larger tumor volume than groups A or B. Furthermore, insignificant tumor was detected in eight patients in group A (13.1%), two in group B (13.3%), and four in group C (7.4%).

CONCLUSION

These findings suggest that the additional sampling of biopsy cores from ALHs does not appear to increase the detection of potentially insignificant cancer, and that biological tumor characteristics seem to be similar irrespective of cancer location on the needle biopsy.