Rate and Extent of Pelvic Lymph Node Dissection in the US Prostate Cancer Patients Treated With Radical Prostatectomy

Purpose: To evaluate the utilization of pelvic lymph node dissection (PLND) and its extent in contemporary US patients, and to correlate it to the detection of pN1 disease. Patients and Methods: A total of 328,710 individuals who received radical prostatectomy between the years 2004 and 2013 were identified within the National Cancer Data Base. The Cochran-Armitage test was used to assess the statistical significance of temporal trends. Logistic regression analysis tested the relationship between the number of lymph nodes removed (LNR) and pN1 rate. Results: Most patients had T2 disease (76.7%) and a Gleason score of 7 (55.9%). Overall, 63.5% of the patients received PLND; this ranged between 58.9% and 72.1% over the study period (P = .8). In patients receiving PLND, mean LNR increased from 6.1 nodes in 2004 to 7.2 nodes in 2013 (P < .001). When stratified by tumor risk, utilization and extent of PLND increased in intermediate- and high-risk tumors, while it decreased in low-risk tumors. Overall pN1 rate was 3.73%, and it increased from 2.9% to 5.3% between 2004 and 2013 (P < .001). In multivariable analysis, LNR was an independent predictor of pN1 (P < .001). Conclusion: The utilization patterns of PLND in the United States have improved, with an increased focus on patients with intermediate- and high-risk disease. Likewise, the extent of PLND has improved to include more lymph nodes. This seems to translate into more accurate tumor, node, metastasis classification system staging, as more patients are being appropriately diagnosed with pN1 disease.