Are Clinically Insignificant Prostate Cancers Really Insignificant Among Korean Men?

Purpose: We aimed to determine whether 12 core-extended biopsies of the prostate could predict insignificant prostate cancer (IPCa) in Koreans reliably enough to recommend active surveillance. Materials and Methods: Two hundred and ninety-seven patients who underwent radical prostatectomy after 12 core-extended prostate biopsies were retrospectively reviewed. 38 cases (12.8%) were shown to be IPCa. Results: The average age was 65.2 years, serum PSA was 5.49 ng/dL, and the PSA density was 0.11. The Gleason scores (GS) were 6 (3+3) in 31, 5 (3+2) in 4, and 4 (2+2) in 3. After radical prostatectomy, higher GS was given in 16 (42.1%), whereas lower GS was given in 1 case (2.6%), as compared with the GS obtained from biopsy. 11 (28.9%) had GS of 7 (3+4) and 5 (13.2%) had GS of 7 (4+3). 6 in GS 7 (4+3) and 1 in GS 7 (3+4) showed prostate capsule invasion and 1 in GS 7 (4+3) had seminal vesicle invasion. Prostate capsule invasion was observed in 1 with GS 6 (3+3). The rate of inaccuracy of the contemporary Epstein criteria was 42.1%. Only PSA density was a reliable indicator of clinically IPCa (odds ratio=1.384, 95% CI, 1.103 to 2.091). Conclusion: Diagnosis of IPCa from a prostate biopsy underestimated the true nature of prostate cancer in as many as 42.1% of Koreans.