Original Article http://dx.doi.org/10.3349/ymj.2012.53.2.358 pISSN: 0513-5796, eISSN: 1976-2437 Yonsei Med J 53(2):358-362, 2012 Are Clinically Insignificant Prostate Cancers Really Insignificant among Korean Men? Chan Dong Yeom,1 Seung Hwan Lee,1 Kyung Kgi Park,2 Sang Un Park,1 and Byung Ha Chung1 1Department of Urology, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul; 2Department of Urology, Yonsei University College of Medicine, Yongin Severance Hospital, Yongin, Korea. Received: February 15, 2011 Revised: May 9, 2011 Accepted: June 9, 2011 Corresponding author: Dr. Byung Ha Chung, Department of Urology, Yonsei University College of Medicine, Gangnam Severance Hospital, 211 Eonju-ro, Gangnam-gu, Seoul 135-720, Korea. Tel: 82-2-2019-3474, Fax: 82-2-3462-8887 E-mail: chung646@yuhs.ac ∙ The authors have no financial conflicts of interest. © Copyright: Yonsei University College of Medicine 2012 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non- Commercial License (http://creativecommons.org/ licenses/by-nc/3.0) which permits unrestricted non- commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Purpose: We aimed to determine whether 12 core-extended biopsies of the pros- tate 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 Ep- stein 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. Key Words: Prostate cancer, gleason score, prostate, clinically insignificant INTRODUCTION Recently, prostate specific antigen (PSA) screening for prostate cancer has become common, and the prostate biopsy technique has evolved, increasingly detecting clinically insignificant prostate cancer.1,2 However, there is no precise guideline for managing clinically insignificant prostate cancer (IPCa) with an early diagnosis. The Epstein criteria is the most frequently used set of definitions for determining whether prostate cancer is clinically insignificant, and this criteria are the basis for starting active surveillance.3,4 However, there are some reports that the reliability of the Epstein criteria can vary by race or regions. This implies that the significance of the Epstein criteria can be different between Western and Asian men.5 Some au- thors have reported that the Epstein criteria may be inaccurate in Asians with pros- tate cancer. They reported that there was higher negative predictive value when the 358 Yonsei Med J http://www.eymj.org Volume 53 Number 2 March 2012