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

Objectives: 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). Materials and methods: Patients with IR PCa treated with IMRT at our institution between September 2000 and November 2010 were analyzed retrospectively. The treatment consisted of IMRT (70–78 Gy in 35–39 fractions) combined with 6 months of neoadjuvant ADT. Salvage ADT was initiated when the prostate-specific antigen level was > 4.0 ng/mL Results: In total, 106 consecutive patients with IR PCa (median age: 70 years old) were analyzed. The median follow-up period was 8.0 years. The overall survival, PCa-specific survival, biochemical failure, and clinical failure rates were 99.0%, 100.0%, 6.8%, and 1.9% at 5 years and 89.1%, 100.0%, 11.3%, and 2.9% at 10 years, respectively. Late recurrence (> 5 years) 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 5 years, and 14.7% and 5.8% at 10 years, respectively. No patient developed grade 4/5 GU toxicities or grade 3–5 GI toxicities. Conclusion: IMRT at a dose up to 78 Gy 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.