Comparative studies of prostate cancers among United States, Chinese, and Japanese patients: characterization of histopathology, tumor angiogenesis, neuroendocrine factors, and p53 protein accumulations

Abstract

Although interracial differences of prostate cancer progression are well recognized, their underlying molecular and cellular mechanisms remain obscure. We compared the histopathologic, immunohistochemical, and molecular characteristics of unselected prostate cancer tissues obtained from U.S., Chinese, and Japanese men. Histopathologic analyses indicated that 74.4% of the prostate cancers in Chinese men were poorly differentiated, compared with 28.6% and 32.8% of the prostate cancers in U.S. and Japanese men, respectively. These differences cannot be attributed to patient age, clinical stage of disease, or methods of tissue sampling. The high proportion of poorly differentiated prostate cancer tissues in the Chinese group was not related to the patients' access to medical service or to geographic background within China. Significantly higher levels of tumor angiogenesis (2- to 4-fold), serotonin (2- to 20-fold), and bombesin (7- to 16-fold), but not chromogranin A, were found in the tissue specimens obtained from Chinese prostate cancer patients compared with those from U.S. and Japanese patients. We also observed marked interracial differences in p53 protein accumulation. The protein was present in 90.2% of Chinese specimens; 17.4% of specimens from U.S. whites; 7.1% of specimens from Japanese men; and 3.7% of specimens from U.S. blacks. Results from multivariate logistic regression analysis demonstrated that p53 protein accumulation, angiogenesis, and serotonin expression in the normal stroma area correlate independently with Chinese versus non-Chinese patient populations.