Extended vs. limited laparoscopic pelvic lymph node dissection for prostate cancer: The value of Partin tables in selection of the need for and the extent of dissection

Abstract

4654 Background: To determine if pelvic lymph node dissection (LND) can be omitted in prostate cancer patients at low risk of nodal metastases according to the Partin tables and to determine the yield on extended vs limited LND in patients at high risk to better define the appropriate template of dissection. Methods: A total of 577 patients with clinically localized prostate cancer underwent a laparoscopic radical prostatectomy (LRP). In the first 363 patients, a cutoff of 1% on the Partin tables’ predicted probability of lymph node invasion (PPLNI) was used to select patients for a limited LND (external iliac nodes only). In the subsequent 214 patients, all patients underwent an extended LND (external iliac, obturator and hypogastric nodes). Patients were classified into 4 groups: Group I, 186 patients with a PPLNI ≤1%, did not undergo a LND; Group II, 110 patients with PPLNI ≤ 1%, underwent an extended LND; Group III, 177 patients with PPLNI >1% underwent a limited LND and Group IV, 104 patients with PPLNI >1%, underwent an extended LND. We compared Group I and II to assess the value of the Partin tables in selecting low risk patients for nodal metastasis. Multivariate logistic regression analysis was performed to compare the node positivity rate between groups III and IV, controlling for preoperative and pathological parameters. Results: None of the patients in group II had a positive lymph node after an extended LND. On multivariate analysis, controlling for PSA, biopsy Gleason, clinical stage, pathological Gleason and stage, and seminal vesicle invasion, the extended LND independently impacted the rate of node positivity with a relative risk (RR) of 15.6 (95% CI 3.7 -66.4, p < 0.001). The median (mean) number of nodes retrieved was 9 (10) and 14 (15) after limited and extended LND respectively (p < 0.001). Conclusions: A lymph node dissection including the external iliac, obturator and hypogastric lymph node groups yields positive nodes more frequently and retrieves a higher total nodal count than the often-performed LND limited to the external iliac nodes. Decision to forgo LND in low risk patients needs to be validated by long-term biochemical recurrence data No significant financial relationships to disclose.