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 prostate 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 bax proteins, as well as directly for the presence of apoptotic 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, bax expression was noted in 76% of samples and was associated with a significantly worse patient prognosis both overall (P< 0.005) and specifically in Chinese patients (P< 0.02). Apoptotic cells were found in 61% of samples, and were significantly associated with the presence of bax expression (P = 0.002), but not patient survival. These results suggest that prostate tumours from non-Japanese Asians are genetically distinct from prostate tumour found in both Japanese and Caucasian patients, and that treatment modalities may need to be tailored for specific population groups.
Copyright 2000 Cancer Research Campaign.