[Indication of repeat prostate biopsy for the diagnosis of prostate cancer]

There is no standard criterion for repeat prostate biopsy in cases with a negative initial biopsy. We retrospectively analyzed our experience of repeat prostate biopsy to establish its indication for the diagnosis of prostate cancer. From April 1997 to March 2005, 35 consecutive patients underwent repeat prostate biopsy at the department of Urology, Asahikawa Medical College Hospital because of clinically suspicious prostate cancer despite a negative initial biopsy. We compared patients' age, number of cores obtained during repeat biopsy, digital rectal examination findings, total prostate volume, the time from the first to the last biopsy, total prostate specific antigen (PSA) value, free PSA/total PSA ratio, PSA density and PSA velocity between cancer-positive and cancer-negative groups. Prostate cancer was detected in 17 of 35 patients (49%). Fifteen patients with prostate cancer were diagnosed by the first repeat biopsy and other 2 patients were diagnosed by the second repeat biopsy. A statistically significant difference was only noted in age and PSA density. Persistently elevated total PSA and a higher PSA density in cases with a negative initial biopsy might be a good indication of repeat prostate biopsy for the diagnosis of prostate cancer.