Predictive value of bcl-2 immunoreactivity in prostate cancer patients treated with radiotherapy.
OBJECTIVE
Recent experimental evidence suggests that overexpression of bcl-2, a protein functioning by blocking apoptosis, may influence the treatment outcome in human tumours, including prostate cancer. To test the clinical implications of this hypothesis, tumours from patients with prostate cancer treated with external beam radiotherapy were investigated for bcl-2 immunoreactivity (IR) and correlated with prognosis and treatment outcome.


METHODS
Bcl-2 IR was evaluated in archival tumour specimens obtained through transurethral resection from 42 patients with localized prostate cancer (T0-T4, N0 and M0). Bcl-2 IR expression was related to stage, grade and cancer-specific survival. Specimens were obtained prior to administrating routine radiotherapy for all patients.


RESULTS
Bcl-2 IR was present in 19/42 (45%) tumours. The bcl-2-positive patients had a significantly longer cancer-specific survival than the bcl-2-negative patients (10.3 versus 3.4 years, P<0.04). At follow-up (7-19 years), nine patients were still alive, 26 patients had died of prostate cancer and seven patients had died of other causes.


CONCLUSIONS
This study indicates that pre-treatment bcl-2 overexpression is related to a favourable outcome in prostate cancer treated with radiotherapy. Low bcl-2 along with a high stage may be a predictor of poor prognosis and these patients might benefit from additional treatment.
Department of Oncology, Umeå University, Sweden.
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Bylund
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Stattin
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Widmark
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Bergh
D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000401:mortality / Q000532:radiotherapy*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D012189:Retrospective Studies; D015996:Survival Rate
D014408:Biomarkers, Tumor; D019253:Proto-Oncogene Proteins c-bcl-2