Single Positive Core Prostate Cancer in a 12-Core Transrectal Biopsy Scheme: Clinicopathological Implications Compared with Multifocal Counterpart

PURPOSE: The incidence of single positive core prostate cancer at the time of biopsy appears to be increasing in the prostate-specific antigen (PSA) era. To determine the clinical implication of this disease, we analyzed surgical and pathological characteristics in comparison with multiple positive core disease. MATERIALS AND METHODS: Among 108 consecutive patients who underwent robotic radical prostatectomy following a diagnosis of prostate cancer based on a 12-core transrectal biopsy performed by the same method in a single institute, outcomes from 26 patients (Group 1) diagnosed on the basis of a single positive biopsy core and from 82 patients (Group 2) with multiple positive biopsy cores were analyzed. RESULTS: The preoperative PSA value, Gleason score, prostate volume, and D'Amico's risk classification of each group were similar. The proportion of intermediate+highrisk patients was 69.2% in Group 1 and 77.9% in Group 2 (p=0.22). Total operative time and blood loss were similar. Based on prostatectomy specimens, only 3 patients (11.5%) in Group 1 met the criteria for an indolent tumor (7.31% in Group 2). Although similarities were observed during preoperative clinical staging (p=0.13), the final pathologic stage was significantly higher in Group 2 (p=0.001). The positive-margin rate was also higher in Group 2 (11.5% vs. 31.7%, p=0.043). Despite similarity in upstaging after prostatectomy in each group (p=0.86), upgrading occurred more frequently in Group 1 (p=0.014, 42.5% vs. 19.5%). No clinical parameters were valuable in predicting upgrading. CONCLUSIONS: Most single positive core prostate cancer diagnoses in 12-core biopsy were clinically significant with similar risk stratification to multiple positive core prostate cancers. Although the positive-margin rate was lower than in multiple positive core disease, an increase in Gleason score after radical prostatectomy occurred more frequently.