Improved biochemical disease-free survival of men younger than 60 years with prostate cancer treated with high dose conformal external beam radiotherapy.
Academic Article
Overview
abstract
PURPOSE: We report the long-term prostate specific antigen relapse-free survival rates and predictors of biochemical outcome for patients 60 years or younger with prostate cancer treated with high dose conformal external beam radiotherapy. MATERIALS AND METHODS: We retrospectively reviewed the records of 740 patients with prostate cancer treated with 3-dimensional conformal radiotherapy or intensity modulated external beam radiotherapy. Patients who also received androgen deprivation therapy were excluded from this analysis. Median radiation dose was 75.6 Gy and median followup was 88 months with a minimum followup of 24 months. Median followup for patients 60 years or younger in this report was 54 months (range 24 to 132). Biochemical failure was defined according to the criteria recommended by the American Society for Therapeutic Radiology and Oncology Consensus Panel. RESULTS: Biochemical failure developed in 20 (21%) of the 96 men 60 years or younger, which was similar to the 22% failure rate observed in 644 patients older than 60. The 5 and 7-year biochemical disease-free survival rates were 82% and 79% in younger men, and 79% and 78% in older men, respectively (p = 0.48). For younger patients who received 81 Gy or greater, the 7-year prostate specific antigen relapse-free survival rates for favorable, intermediate and unfavorable risk patients were 96%, 87% and 50%, respectively. Multivariate analysis revealed that among patients 60 years or younger the most important predictor of biochemical relapse was radiation doses less than 75.6 Gy followed by Gleason score greater than 7. CONCLUSIONS: Men with prostate cancer 60 years or younger treated with high dose radiotherapy have an excellent biochemical outcome and fare as well as older patients. The use of conventional dose levels in patients 60 years or younger was associated with an 8-fold increase in the biochemical relapse rate and these doses should not be considered appropriate for the treatment of localized prostate cancer.
