INTERRACIAL COMPARATIVE-STUDY OF PROSTATE-CANCER IN THE UNITED-STATES, CHINA, AND JAPAN

The interracial differences of prostate cancer progression have long b een documented; however, underlying molecular and cellular mechanisms remain obscure. This study focuses on the histopathologic, immunohisto chemical, biochemical, and molecular characterization of prostate canc er tissues unselectively obtained from US, Chinese, and Japanese men. Histopathologic analyses indicate that 74.5% of the prostate cancers i n Chinese patients were poorly differentiated, compared with 28.6 and 32.8% of the prostate cancers in US and Japanese men, respectively. Th ese differences cannot be attributed to patient age, clinical stage of disease, or methods of tissue sampling. Furthermore, the high proport ion of poorly differentiated prostate cancer tissues in the Chinese gr oup was not related to the patients' access to medical service or thei r geographic origins within China. We found significantly higher level s of tumor angiogenesis (2- to 4-fold), serotonin (2- to 20-fold), and bombesin (7- to 16-fold), but not chromogranin A, in tissue specimens obtained from Chinese prostate cancer patients compared with those fr om US and Japanese patients. We also found marked differences in p53 p rotein accumulation among various ethnic groups. The p53 protein was f requently detected in prostate cancer tissue specimens from Chinese (9 0.2%), but less frequently in US blade (3.7%), US white (17.4%), and J apanese (7.1%) men. Further analysis of 31 prostate cancer tissues fro m Chinese men indicated that mutational changes in the p53 gene occurr ed between exons 5 and 8. (C) 1998 Wiley-Liss, Inc.