RESUMO
AIM: To retrospectively investigate the biochemical outcome following delayed radiotherapy in patients with prostate cancer. PATIENTS AND METHODS: From July 2000 to November 2008, 144 consecutive patients with localized prostate cancer underwent radiotherapy and androgen-deprivation therapy. Biochemical progression-free survival was compared in patients who began radiotherapy >6 months (delayed group) with these who began ≤ 6 months (non-delayed group) from diagnosis by biopsy. Treatment selection bias was adjusted by the propensity score method. RESULTS: After a median follow-up of 64 months, the 5-year biochemical progression-free survival of the delayed and non-delayed groups was 87.4% (95% confidence interval, CI=69.7-95.1%) and 96.6% (95% CI=89.6-98.9%), respectively (p=0.03). Delayed radiotherapy was the only independent risk factor for biochemical progression (hazard ratio=3.97, 95% CI 1.07-14.7, p=0.04). The results were validated by propensity score analysis. CONCLUSION: Delaying radiotherapy by >6 months increases the risk of biochemical progression in patients with localized prostate cancer.