Variation in pelvic lymph node dissection among patients undergoing radical prostatectomy by hospital characteristics and surgical approach: results from the National Cancer Database

Purpose: Clinical practice guidelines recommend pelvic lymph node dissection at the time of surgery for intermediate or high risk prostate cancer. Therefore, we examined the relationship of pelvic lymph node dissection and detection of lymph node metastasis with hospital characteristics and surgical approach among patients with prostate cancer.

Materials and methods: Using the National Cancer Data Base we identified surgically treated patients with pretreatment intermediate or high risk disease from 2010 to 2011. Primary outcomes were treatment with pelvic lymph node dissection and extended pelvic lymph node dissection, as well as the detection of lymph node metastasis. Multivariate logistic regression models were used to test whether hospital characteristics and surgical approach were associated with each outcome.

Results: Among the 50,671 surgically treated patients 70.8% (35,876) underwent concomitant pelvic lymph node dissection, 26.6% (9,543) underwent extended pelvic lymph node dissection and 4.5% (1,621) had lymph node metastasis. Pelvic lymph node dissection was performed more often at high volume vs low volume hospitals (81.2% vs 65.4%, adjusted OR 2.20, p=0.01), but less frequently with robotic assisted radical prostatectomy vs open radical prostatectomy (67.5% vs 81.8%, adjusted OR 0.30, p <0.001). Higher odds ratios for lymph node metastasis were also demonstrated with high vs low volume (OR 1.35, p=0.01) and academic vs community hospitals (OR 1.35, p <0.001). However, patients treated with robotic assisted radical prostatectomy had lower odds ratios for lymph node metastasis compared to those undergoing open radical prostatectomy (OR 0.56, p <0.001).

Conclusions: In this cohort a third of patients are not receiving guideline recommended treatment with pelvic lymph node dissection for prostate cancer. Pelvic lymph node dissection and detection of lymph node metastasis varied by surgical approach, hospital volume and academic status.