Preprostatic lymph nodes in prostate cancer hot or not? Impact on oncological outcome after radical prostatectomy

To assess the impact of preprostatic lymph node invasion on prostate cancer patients' outcome after radical prostatectomy. It is known that invasion of pelvic lymph nodes is associated with worse oncological outcome, but little is known about invasion of preprostatic lymph nodes. We hypothesized that positive preprostatic lymph nodes may not be as harmful as positive pelvic lymph nodes.

A total of 11,107 consecutive patients treated for prostate cancer with radical prostatectomy between 2013 and 2017 were evaluated. 1575 (14.2%) had some type of lymph node invasion, 53 (0.5%) had only one positive preprostatic lymph node and 705 (6.3%) had only one positive pelvic lymph node.

Median follow-up was 37.7 months (interquartile range: 24.6-58.7 months). Baseline characteristics of the overall cohort were not statistically significant between the preprostatic vs. pelvic lymph node invasion groups, except for robot-assisted operation (64.2 vs. 32.3%, p < 0.001) and count of removed lymph nodes (16 vs. 19, p < 0.001). There was no statistically significant difference in 3-years biochemical recurrence rate (56.2 vs. 65.8%, p = 0.5), 3-years metastases free survival rate (87.4 vs. 95.5%, p = 0.5) and overall cancer-specific mortality (1.9 vs 1.0%) between the two groups.

Preprostatic lymph node invasion seems to have a similar harmful effect as pelvic lymph node invasion and thus, if detected, may alter treatment and follow-up strategy. Therefore, it is important to perform a histological analysis when removing the preprostatic tissue.