Bcl-2 immunoreactivity in prostate tumorigenesis in relation to prostatic intraepithelial neoplasia, grade, hormonal status, metastatic growth and survival.
The Bcl-2 protein prolongs cell survival by overriding apoptosis. To explore the role of Bcl-2 in prostate tumorigenesis, immunoreactivity for Bcl-2 was examined in untreated and androgen-deprived tumours and lymph node metastasis. Following the transurethral resection, 150 untreated patients were maintained under surveillance until death or for a minimum of 11 years, and castration was performed at symptomatic progression. The Bcl-2 index (BI) was defined as the percentage of immunoreactive cells in a tumour. The mean BI was 12 in the untreated tumours, and BI was significantly higher in high-grade tumours, mean BI 17, than in low-grade tumours, mean BI 6. There was no correlation between BI and stage or metastatic disease, nor did BI predict cancer-specific survival. In 16 androgen-deprived, but non-relapsed tumours, the mean BI was 54, at a mean time of 22 months after castration, indicating a permanent increase of Bcl-2 protein expression after androgen withdrawal. In six patients, tissues from the prostate tumour and obturator lymph node metastasis were available. Four primary tumours immunostained for Bcl-2, but only one metastasis stained. Foci of highgrade prostatic intraepithelial neoplasia (PIN) were present in 44 of the 150 untreated tumours. All PIN foci were intensely immunoreactive for Bcl-2, and mean BI was 79, suggesting that Bcl-2 protein expression is associated with early prostate tumorigenesis.
Stattin
P
P
Department of Urology and Andrology, Umeå University, Sweden.
Damber
J E
JE
Karlberg
L
L
Nordgren
H
H
Bergh
A
A
D000368:Aged; D000728:Androgens / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008297:Male; D009376:Neoplasms, Hormone-Dependent / Q000378:metabolism / Q000473:pathology / Q000556:secondary; D009919:Orchiectomy; D011379:Prognosis; D019048:Prostatic Intraepithelial Neoplasia / Q000378:metabolism* / Q000473:pathology / Q000556:secondary; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D015996:Survival Rate
D000728:Androgens; D019253:Proto-Oncogene Proteins c-bcl-2