Prostate tumours from an Asian population: examination of bax, bcl-2, p53 and ras and identification of bax as a prognostic marker

Molecular studies have suggested that ethnicity may play a significant role in prostate tumorigenesis, but no information exists for groups other than Caucasian or Japanese patients. We examined 62 archival samples of prostat e tumours from Asians of non-Japanese origin for the over-expression of p53 , for the possible presence of mutated ras genes, for the overexpression of the bcl-2 and bar proteins, as well as directly for the presence of apopto tic cells by the TUNEL methodology. Gene lesions of both ras (0%) and p53 ( 3%) were rare. While bcl-2 expression was not observed in any sample, bar e xpression was noted in 76% of samples and was associated with a significant ly worse patient prognosis both overall (P < 0.005) and specifically in Chi nese patients (P < 0.02). Apoptotic cells were found in 61% of samples, and were significantly associated with the presence of bar expression (P = 0.0 02), but not patient survival. These results suggest that prostate rumours from non-Japanese Asians are genetically distinct from prostate tumour foun d in both Japanese and Caucasian patients, and that treatment modalities ma y need to be tailored for specific population groups. (C) 2000 Cancer Resea rch Campaign.