Low incidence of late recurrence in patients with intermediate-risk prostate cancer treated by intensity-modulated radiation therapy plus short-term androgen deprivation therapy.

Abstract

This study evaluated the long-term outcomes of intensity-modulated radiation therapy (IMRT) combined with short-term neoadjuvant androgen deprivation therapy (ADT) in patients with intermediate-risk (IR) prostate cancer (PCa). Patients with IR PCa treated with IMRT at our institution between September 2000 and November 2010 were analyzed retrospectively. The treatment consisted of IMRT (70-78Gy in 35-39 fractions) combined with 6months of neoadjuvant ADT. Salvage ADT was initiated when the prostate-specific antigen level was > 4.0ng/mL RESULTS: In total, 106 consecutive patients with IR PCa (median age: 70years old) were analyzed. The median follow-up period was 8.0years. The overall survival, PCa-specific survival, biochemical failure, and clinical failure rates were 99.0%, 100.0%, 6.8%, and 1.9% at 5years and 89.1%, 100.0%, 11.3%, and 2.9% at 10years, respectively. Late recurrence (> 5years) was observed in three cases (2.8%). The cumulative incidence rates of genitourinary (GU) and gastrointestinal (GI) toxicities (grade 2/3) were 10.5% and 5.8% at 5years, and 14.7% and 5.8% at 10years, respectively. No patient developed grade 4/5 GU toxicities or grade 3-5 GI toxicities. IMRT at a dose up to 78Gy combined with short-term neoadjuvant ADT resulted in excellent long-term disease-free outcomes with acceptable morbidities among patients with IR PCa. In addition, the incidence of late recurrence was very low. Further investigation is warranted to confirm our findings.