“…Selection of patients in our study was similar to that in previous reports [10,11], so the difference may be attributed to the racial difference rather than selection bias. Some have reported that the cellular composition of BPH in the prostates of American and Chinese men is different [14,15], and this difference also exists among white American, black American, and Japanese men [16], resulting in racial differences in PSA, PSA density, and the incidence of clinical BPH. The slope of linear regression of PSA and PV was 3.68 in Korean men with biopsy-proven BPH reported by Lee et al [11], higher than in white men reported by Hochberg et al [7].…”