Lymph node metastases are a major prognostic factor in prostate cancer (Gervasi et al. 1989). Studies correlating the number of positive lymph nodes with cancer outcome show a negative trend for progression-free survival (PFS) and overall survival (OS) with increasing nodal tumor burden (Boorjan et al. 2007; Briganti et al. 2009).

Since the dawn of the PSA-era a shift toward early localized disease has occurred and the relative number of lymph node-positive prostate cancer patients has decreased (Palapattu et al. 2004). Nowadays the prevalence of pN+ disease in RRP-series is 2.5–5 % (Nguyen et al. 2009; Paul et al. 2009), a cN+ situation is even more rare. Data solely concerning the subgroup of cN+ patients is sparse and hence the optimal treatment approach for clinically LN-positive prostate cancer patients is unclear. Evidence can only be extrapolated from large studies either pooling stage III-IV patients (thus also including locally advanced T3-4 patients or pN+ patients with histologically proven nodal metastases) or studies on “high-risk” patients (which might also include patients with a statistically high risk for lymphatic disease predicted by nomograms without overt metastatic disease).

Although the 7th edition of the AJCC cancer staging manual groups N+ and M+ patients together as stage IV, today long-term survival in patients with lymphatic disease is not uncommon. According to the current NCCN treatment guideline on prostate cancer (version 2.2014) cN+ patients should either receive ADT alone or RT in conjunction with 2–3 years of neoadjuvant/concomitant or adjuvant ADT.

Patients unable or unwilling to undergo any treatment can also be offered observation. Due to the fact that even in patients with node-positive prostate cancer the onset of symptomatic disease progression might take months to years, observation might prove a reasonable approach in elderly patients or patients unable or unwilling to go through local or systemic treatment. EORTC 30891 looked at histologically confirmed prostate cancer patients (T0-4) with or without nodal involvement (cN0-2) without metastatic disease (M0) ineligible for local treatment and randomized between immediate and deferred ADT. In the delayed treatment arm ADT was initiated when symptomatic disease progression occurred. At a median FU of 7.8 years there was a small but statistically significant difference concerning OS favoring immediate ADT of 42 versus 48 %. An advantage in DSS or symptom free survival could not be shown. Median time to initiation of ADT in the deferred arm was 7 years (Studer et al. 2006).