World J Urol (2012) 30:265–269 267 Fig. 1 Percentage of bone metastasis according to baseline symptom, PSA, and biopsy Gleason scores Table 2 Comparison of diagnostic accuracy for assessment of bone metastasis according to PSA levels PSA · 20 and GS · 7 74.7 92.9 63.9 95.6 PSA · 10 and GS · 7 98.8 84.3 51.3 99.8 Sensitivity (%) SpeciWcity (%) PPV (%) NPV (%) Discussion PSA prostate-speciWc antigen, GS Gleason scores, PPV positive predictive value, NPV negative predictive value We observed bone metastasis in 14.3% of newly diag- nosed Pca, which is higher than that in the United States (8.9%) [10]. and lower than that in Japan (22.2%) [8]. Recently, the epidemiology of prostate cancer in the Asian population has changed, thanks to the increasing awareness of the disease entity, the advent of the PSA testing for screening, and the increase in life expectancy of the male population [11]. In South Korea, the inci- dence of prostate cancer is rapidly increasing, ranking Wfth among the most common cancers in the male popu- lation in 2007 [12]. Therefore, our lower incidence of metastatic Pca compared to previous Asian studies [8, 13] might be due to the increasing awareness of PSA screening in Korea. Fig. 2 Receiver operant characteristic curve for data obtained from patients with PSA · 20, Gleason score · 7 (a) and PSA · 10, Glea- son score · 7 (b) with bone metastasis correlation In our study, 83 men had a positive bone scan. Among them, 21 patients (25.3%) had serum PSA · 20 ng/mL and GS · 7 at the time of the diagnosis. The aim of bone scan is to detect occult locoregionally advanced or distant meta- static disease that would alter the primary treatment plan. ConWning the bone scan analysis to less strict criteria would have increased the sensitivity but decreased positive predic- tive ability. However, what is important when determining 123