Long-Term Mortality in Patients with Positive Lymph Nodes at the Time of Radical Prostatectomy

The aim of this study was to determine prognostic factors and to provide long-term mortality data in patients with positive lymph nodes at the time of radical prostatectomy in a sample with long-term follow-up.

A total of 527 patients with complete data sets treated in the years 1992-2014 were studied. The median follow-up was 7.2 years. The median number of removed lymph nodes was 15. Age, year of surgery, Gleason score, local tumor stage, prostate-specific antigen level, lymph node density, lymph node count and the number of positive lymph nodes were included in multivariable competing risk analyses with prostate cancer mortality as endpoint.

After 20 years, 28% of patients (95% CI 20-36%) died from non-prostate cancer (competing) causes, whereas 29% (95% CI 23-36%) died from prostate cancer. Only lymph node density (stratified by the median of 11.1%; hazard ratio [HR] 1.66, 95% CI 1.04-2.64, p = 0.0340) and Gleason score (8-10 vs. <8: HR 5.97, 95% CI 3.18-11.23, p < 0.0001) were independent predictors of prostate cancer mortality. Patients with a Gleason score <8 and a lymph node density < median had a 20-year prostate cancer mortality of only 5% (95% CI 0-10%), whereas this rate in patients with Gleason score 8-10 and a lymph node density ≥ median was 44% (95% CI 32-56%), p < 0.0001.

Mortality in patients with positive lymph nodes was determined by tumor aggressiveness and the relative extent of spread; neither the year of surgery nor the number of removed lymph nodes was associated with outcome. Patients with a lymph node density of <11.1% and a Gleason score <8 had an excellent long-term outcome.