Background: The present study investigated the long-term outcome of patients with localized high-risk prostate cancer after definitive conformal radiotherapy.
Patients and methods: Ninety-one consecutive patients with stage T1-T4 prostatic carcinoma were treated from 1996 through 2000. Each patient had at least one of the following risk factors: stage > T2b (UICC 1997; 55 patients), Gleason score > 7 (24 patients), or pre-treatment PSA > 20 ng/mL (40 patients). All patients received a conformal radiotherapy of the prostate (median dose, 70 Gy), eighty-three patients (91%) combined with temporary androgen deprivation (median duration, 4 months). All patients were followed continuously during a median of 5.2 years (range, 0.9 to 8.8 years). Biochemical failure after irradiation was defined as a PSA greater than 0.4 ng/mL and three consecutive serum PSA elevations.
Results: The 5- and 7-year overall survival rates were 86% and 74%, respectively. The 5- and 7-year biochemical disease-free survival (bDFS) rates were 78% and 66% respectively. The most important predictors of bDFS were Gleason score and central axis dose of 70 Gy or higher. PSA nadir (median, 0.1 ng/mL) was not predictive of subsequent biochemical disease-free survival.
Conclusion: Our study confirms the findings of others and encourages us to proceed with this treatment policy for T1-T4 high-risk prostate cancer modified by using higher doses and long-term androgen deprivation.