Prostate cancer sampled on sextant needle biopsy: Significance of cancer on multiple cores from different areas of the prostate

Objectives. To determine the relationship between the location of positive sites, when more than one sextant site shows prostate cancer in a given patient, and pathologic stage, tumor volume, and margin status if radical prostatectomy is performed. Methods. We performed biopsies using a spring-loaded biopsy gun on 343 Stage T1c (nonpalpable) radical prostatectomy specimens from each sextant site. Results. In 56 cases, carcinoma was identified in two separate sextant sites. In 38 cases, the sites were vertical to each other (ie, left apex, left mid); in 8 cases, the sites were diagonal (ie, left apex, right mid); in 5 cases, the sites were horizontal (ie, left apex, right apex); and in 5 cases, they were not contiguous but were separated by an uninvolved sextant site (ie, left apex, left base). Tumors were more likely to be multifocal in cases with diagonally positive biopsies (P <0.0001) and horizontally positive biopsies (P <0.0001) than in those with vertically positive biopsies. No significant differences were found in organ-confined status and margin positivity among cases with different positive biopsy locations. The dominant tumor nodule was larger (mean 2.76 cc) in cases with noncontiguously positive biopsies than in all other groups combined (mean 1.44 cc) (P = 0.017). Conclusions. When more than one sextant site shows cancer, there are differences in terms of whether the tumors sampled are multifocal versus solitary depending on which sites are positive. However, no significant differences were found in predicting pathologic stage and margin positivity.