Predicting biochemical recurrence-free survival for patients with positive pelvic lymph nodes at radical prostatectomy

Purpose: We evaluated predictors of freedom from biochemical recurrence in patients with pelvic lymph node metastasis at radical prostatectomy.

Materials and methods: Of 207 patients with lymph node metastasis treated with radical prostatectomy and bilateral pelvic lymph node dissection 45 received adjuvant androgen deprivation therapy and 162 did not. Cox proportional hazards regression models were used to investigate predictors of biochemical recurrence after radical prostatectomy. Recurrence probability was estimated using the Kaplan-Meier method.

Results: A median of 13 lymph nodes were removed. Of the patients 122 had 1, 44 had 2 and 41 had 3 or greater positive lymph nodes. Of patients without androgen deprivation therapy 103 had 1, 35 had 2 and 24 had 3 or greater positive lymph nodes while 69 experienced biochemical recurrence. Median time to recurrence in patients with 1, 2 and 3 or greater lymph nodes was 59, 13 and 3 months, respectively. Only specimen Gleason score and the number of positive lymph nodes were independent predictors of biochemical recurrence. Recurrence-free probability 2 years after prostatectomy in men without androgen deprivation with 1 positive lymph node and a prostatectomy Gleason score of 7 or less was 79% vs 29% in those with Gleason score 8 or greater and 2 or more positive lymph nodes.

Conclusions: Prognosis in patients with lymph node metastasis depends on the number of positive lymph nodes and primary tumor Gleason grade. Of all patients with lymph node metastasis 80% had 1 or 2 positive nodes. A large subset of those patients had a favorable prognosis. Full bilateral pelvic lymph node dissection should be done in patients with intermediate and high risk cancer to identify those likely to benefit from metastatic node removal.