Do additional cores from cancer-suspicious lesions on transrectal ultrasound improve prostate cancer detection including index tumors over 12-core systematic biopsy?

OBJECTIVE: The efficacy of additional cores from cancer-suspicious lesions by transrectal ultrasound (TRUS) for the detection of prostate cancer (PCa) was assessed. MATERIALS AND METHODS: Data were collected from 4144 men who underwent systematic 12-core biopsy with no cancer-suspicious lesions (Group A: 3256 cases) or 13- or more-core (systematic 12 core + additional cores) biopsy with cancer-suspicious lesions (Group B: 888 cases) on TRUS-guided biopsy. The effect of additional biopsy cores on the cancer detection rate was investigated. RESULTS: PCa was detected in 1006 (30.9%) cases in Group A and 485 (54.6%) cases in Group B (p < 0.001). In 370/485 (76.3%) patients in Group B, cancer was detected from the additional cores from TRUS suspicious lesions. Logistic regression analysis showed that the number of biopsy cores was the most significant factor for cancer detection (hazards ratio: 2.6 [2.221–3.043], p < 0.001]. Additional core biopsies did not increase the detection rate of index tumors (p < 0.001). However, the Gleason score of index tumors was higher than that of systematic cores (p < 0.001). Kaplan–Meier analysis showed no significant differences in survival according to biopsy number and location of index tumors (log-rank test: p = 0.583, p = 0.165, respectively). CONCLUSION: Although additional core biopsies can increase the cancer detection rate, they do not increase the detection rate of index tumors. Biopsy core number and the location of index tumors had no effect on biochemical outcomes.