Clinicopathologic Differences Between Prostate Cancers Detected During Initial and Repeat Transrectal Ultrasound-Guided Biopsy in Korea

ABSTRACT

PURPOSE: The aim of this study was to investigate clinicopathologic differences between prostate cancer (PCa) detected at initial and repeat transrectal ultrasound-guided prostate biopsy in a large Korean cohort. MATERIALS AND METHODS: From 2000 through 2012, a total of 7,001 patients underwent transrectal ultrasound-guided prostate biopsy at 6 centers in Daegu and Gyeongbuk provinces. Of these 7,001 patients, the initial biopsy was positive for PCa in 2,118 patients. Repeat biopsy was performed in 374 of the 4,883 patients with an initial negative finding and a persistently elevated prostate-specific antigen (PSA) level, nodules or asymmetry by digital rectal examination (DRE), high-grade prostatic intraepithelial neoplasia, or atypical small acinar proliferation. Numbers of biopsy cores varied from 6 to 12 according to center and biopsy date. RESULTS: Cancer was diagnosed in 2,118 of the 7,001 patients (30.3%) at initial biopsy and in 86 of the 374 patients (23.0%) at repeat biopsy. The repeat biopsy rate was 5.3%. Mean PSA values were 68.7+/-289.5 ng/mL at initial biopsy and 18.0+/-55.4 ng/mL at repeat biopsy (p<0.001). The mean number of cancer-positive cores per biopsy was 5.5+/-3.5 for initial biopsy and 3.0+/-2.9 for repeat biopsy (p<0.001). Mean Gleason score was 7.5+/-1.4 at initial biopsy and 6.6+/-1.3 at repeat biopsy (p<0.001). For detected cancers, the low-stage rate was higher for repeat biopsy than for initial biopsy (p=0.001). CONCLUSIONS: Cancers detected at repeat biopsy tend to have lower Gleason scores and stages than cancers detected at initial biopsy. The present study shows that repeat biopsy is needed in patients with a persistently high PSA or abnormal DRE findings.