Evaluating the Impact of Prostate Only Versus Pelvic Radiation for N+ Prostate Cancer.

At least 40% of the patients with prostate cancer (PC) present with positive lymph nodes (N1). The optimal treatment strategy for these patients remains controversial. Although androgen deprivation therapy (ADT) is still often initiated as only treatment, the results are disappointing. Recent studies support the use of more aggressive therapies including external beam radiotherapy (EBRT) and ADT. The retrospective studies supporting the additional use of EBRT in N1 PC patients are however not conclusive regarding to the extent of radiation field. Even after an EPLND, there might be a role for pelvic EBRT in irradicating microscopic disease. However pelvic irradiation irrevocably results in increased toxicity. Moreover, in node negative (N0) PC patients the addition of pelvic EBRT has not resulted in improved outcome in randomised trials. However in the setting of Tumor Node Metastasis pathological stage (p)N1, proven on pathological examination, PC patients this has never been evaluated so far. This trial aims to answer the question whether or not pelvic EBRT is beneficial in pathological N1 PC patients. It is also important to realise that not all pathological N1 PC patients have similar outcome. There is a significant impact of number of positive lymph nodes on outcome, with two positive nodes being suggested as a significant cut-off value in predicting survival in pathological N1 PC patients. By stratifying the patients according to the number of lymph nodes involved this study will add to the proper selection of those patients who will benefit most of pelvic EBRT and avoid toxicity in patients who have no benefit of pelvic EBRT. Additionally, small RNAs constitute potentially valuable markers for the diagnosis, prognosis, and therapeutic choices in PC patients. Blood samples will be collected to examine the potential role of miRNAs as a biomarker and to develop a prognostic signature for clinical relapse-free survival. The results of this trial will serve as