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

Abstract

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. © 2000 Cancer Research Campaign

Pathologic characteristics of prostatic adenocarcinomas: a mapping analysis of Korean patients

“…In Asian patients, p53 changes (protein overexpression or gene mutation) are not common, ranging from 3% to approximately 10%. 7,9,10 Our result, 9.8%, is very similar to the data from Singapore and Japan. There is no explanation about low p53 changes among Asian prostatic adenocarcinoma yet.…”

“…7,9,22 HPIN is found near prostatic adenocarcinoma, usually within 2 mm, but it is very difficult to find without a mapping analysis on numerous prostatic tissues. In Korea, Lee et al 19 were the first to report pathological studies of a mapping analysis.…”

“…Data on Japanese and Singaporean patients have shown that p53 overexpression and mutation occur in prostate cancer with a considerably lower frequency than those found in Western populations. 7,9,10 In addition to data with discordant rates of p53 change in prostate tumors from Western and Japanese populations, a considerably higher frequency of ras mutation is found in Japanese patients, up to 25%. 11,12 High-grade prostatic intraepithelial neoplasm (HPIN) is the most important candidate for the premalignant condition of prostatic carcinogenesis and is frequently found near the prostatic adenocarcinoma.…”

“…It is the ninth common male cancers (2.2%; year 2000) and is the tenth common cause of death by male cancer (2.3 deaths/100 000; year 2000) in Korea. 7 During the past 5 years, its significance in the incidence and cancer-related death of prostate cancer patient has now been increasing (almost twice) in Korea, 7 like other Asian country (eg, Singapore 8 ). Thus, it is important to understand the pathologic characteristics and prognostic factors of prostate cancer in Korea.…”

NOXA and PUMA Expression Add to Clinical Markers in Predicting Biochemical Recurrence of Prostate Cancer Patients in a Survival Tree Model

“…Thus far, most studies addressing this question have focused on BAX, a proapoptotic protein that elicits its effect at the level of the mitochondrial outer membrane where it promotes mitochondrial depolarization, a key event in the intrinsic apoptotic pathway. Although it is clear from several immunohistochemistry (IHC) studies that BAX is expressed in the large majority of tumors, the association between BAX expression and PCa progression remains uncertain (18,(23)(24)(25)(26).…”