Failure free survival following brachytherapy alone for prostate cancer: comparison with external beam radiotherapy.

Abstract

To compare failure free survival (FFS) for brachytherapy (BT) alone and external beam radiotherapy (EBXRT) alone. Between 12/88 and 12/95, 1527 and 695 T(1) or T(2) Nx-No Mo prostate cancer patients (from the Arizona Oncology Services database) were treated with either EBXRT or BT, respectively. The median age was 74 years. Median follow-up for EBXRT and BT patients was 41.3 and 51.3 months, respectively. Overall FFS at 5 years for EBXRT and BT were 69 and 71%, respectively (P=0.91). No significant difference in FFS at 5 years was observed between EBXRT and BT for either T(1) (78 vs. 83%, P=0.47) or T(2) (67 vs. 67%, P=0.89) tumours. Superior outcomes for Gleason 8-10 lesions treated with EBXRT vs. BT (5 years FFS 52 vs. 28%, P=0.04) were observed; outcomes for lower grade lesions when analysed by Gleason score alone did not significantly differ according to treatment received. Patients with initial PSA values 10-20 ng/dl had an improved FFS with EBXRT vs. BT (70 vs. 53%, P=0.001); outcomes for patients with initial PSA ranges 0-4 ng/dl, >4-10 ng/dl and >20 ng/dl did not differ significantly with treatment received. EBXRT and BT appear to be equally efficacious for low-risk patients having T(1)/T(2) disease with Gleason scores <6 and PSA <10 ng/dl. Patients with Gleason scores 8-10 or PSA >10 ng/dl-<20 ng/dl) appear to fare worse with BT alone compared with EBXRT. Neither EBXRT nor BT were particularly effective for patients with a presenting PSA >20 ng/dl.