title: Comparison of prostate-specific antigen and hormone levels among men in Singapore and the United States.
abstract: Prostate cancer incidence rates markedly vary between countries. The highest rates of prostate cancer are observed in Western countries such as the United States, whereas the lowest rates are seen in Asian countries such as Singapore. To gain an understanding of the difference in prostate cancer burden between low-risk and high-risk populations, we examined serum prostate-specific antigen (PSA) levels among Singapore-Chinese men (n = 315) from the Singapore Chinese Health Study and African-American (n = 440), U.S. White (n = 355), U.S. Latino (n = 523), and Japanese-American (n = 349) men from the Hawaii-Los Angeles Multiethnic Cohort Study. All men had no history of prostate cancer at the time of blood draw. PSA measurements were assayed by one centralized diagnostic facility. Testosterone and 3alpha-androstanediol glucuronide levels were examined in a subsample of men. Scheffe's multiple comparison tests were used to evaluate differences in PSA and hormone levels between groups. PSA levels among the Singapore-Chinese (geometric mean = 1.43 ng/mL) were similar to that of African-Americans (1.46 ng/mL), U.S. Whites (1.28 ng/mL), and Japanese-Americans (1.22 ng/mL) and significantly higher than U.S. Latinos (1.18 ng/mL; P = 0.038). Although there was a strong correlation (R2= 0.89) between PSA levels and U.S. ethnic group-specific prostate cancer incidence rates before PSA screening (1983-1987), the levels among the Singapore-Chinese completely failed to relate to their low incidence rate. Testosterone and 3alpha-androstanediol glucuronide levels did not reflect racial/ethnic patterns of disease. Our results highlight a potentially large group of Singapore-Chinese men with undiagnosed prostate cancer. Given that the overall mortality rate of prostate cancer in Singapore is low, these undiagnosed cancers may be of nonaggressive type. Alternatively, PSA may be a poor marker of prostate cancer in this low-risk population.
authors: Department of Preventive Medicine, Keck School of Medicine, University of Southern California, USC/Norris Comprehensive Cancer Center, 1441 Eastlake Avenue, Los Angeles, CA, 90089-9175, USA. ionachen@usc.edu
authors: Iona
authors: I
authors: Cheng
authors: Mimi C
authors: MC
authors: Yu
authors: Woon-Puay
authors: WP
authors: Koh
authors: Malcolm C
authors: MC
authors: Pike
authors: Laurence N
authors: LN
authors: Kolonel
authors: Brian E
authors: BE
authors: Henderson
authors: Daniel O
authors: DO
authors: Stram
mesh_terms: D017677:Age Distribution; D000368:Aged; D015113:Androstane-3,17-diol / Q000097:blood*; D005006:Ethnicity; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000401:mortality; D012846:Singapore / Q000453:epidemiology; D013739:Testosterone / Q000097:blood*; D014481:United States / Q000453:epidemiology
chemical_list: D015113:Androstane-3,17-diol; D013739:Testosterone; D017430:Prostate-Specific Antigen