Favorable outcomes in locally advanced and node positive prostate cancer patients treated with combined pelvic IMRT and androgen deprivation therapy

BACKGROUND: The most appropriate treatment for men with prostate cancer and positive pelvic nodes, N+, is an area of active controversy. We report our 5-years outcomes in men with locally advanced prostate cancer (T1-T4N0-N1M0) treated with definitive radiotherapy encompassing the prostate and pelvic lymph nodes (intensity modulated radiotherapy, IMRT) and long-term androgen deprivation therapy (ADT). MATERIAL AND METHODS: Of the 138 consecutive eligible men all living patients have been followed up to almost 5 years. Survival endpoints for 5-year biochemical failure-free survival (BFFS), relapse-free survival (RFS), prostate cancer-specific survival (PCSS), and overall survival (OS) were assessed by Kaplan-Meier analysis. Univariate and multivariate Cox regression proportional hazards models were constructed for all survival endpoints. The RTOG morbidity grading system for physician rated toxicity was applied. RESULTS: Patients with locally advanced T3-T4 tumors (35 %) and N1 (51 %) have favorable outcome when long-term ADT is combined with definitive radiotherapy encompassing pelvic lymph nodes. The 5-year BFFS, RFS, PCSS and OS were 71.4, 76.2, 94.5 and 89.0 %, respectively. High Gleason sum (9–10) had a strong independent prognostic impact on BFFS, RFS and OS (p = 0.001, <0.001, and 0.005 respectively). The duration of ADT (= > 28 months) showed a significant independent association with improved PCSS (p = 0.02) and OS (p = 0.001). Lymph node involvement was not associated with survival endpoints in the multivariate analysis. The radiotherapy induced toxicity seen in our study population was moderate with rare Grade 3 GI side effects and up to 11 % for Grade 3 GU consisting mainly of urgency and frequency. CONCLUSION: Pelvic IMRT in combination with long-term ADT can achieve long-lasting disease control in men with N+ disease and unfavorable prognostic factors. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13014-015-0540-3) contains supplementary material, which is available to authorized users.