BETHESDA, MD USA (UroToday.com) - Dr. Jodi Maranchie began her presentation by introducing historic data, including autopsy studies, that showed the unpredictability of nodal metastases, with 7% of metastases being hilar, 27% located at the ipsilateral vessels, and 20% supraclavicular (Saitoh et al. J Urol 1982). Nodal staging improved over the next two decades with refinement in axial imaging. (Studer et al. J Urol 1990) described a 58% false positive rate and 4% false negative rate of nodal staging with CT scan.
Dr. Maranchie reviewed the data of EORTC 30881 where 722 cN0 patients were randomized to receive radical nephrectomy with full template lymph node dissection vs radical nephrectomy alone. No survival benefit was identified, and only 4% of patients had positive nodes (Blom, Eur Urol 2009). Among patients with clinically positive lymph nodes, Pantuck et al. demonstrated a survival advantage of 5 months (J Urol 2003). Aside from lymphadenectomy, the other factor associated with survival benefit was tumor grade.
This highlights the importance of predicting which patients would benefit from lymph node dissection. Dr. Maranchie reviewed the work by (Blute et al. J Urol 2004) that identified 5 factors on multivariate analysis for lymph node involvement: Grade 3-4 (OR 5.25, p < 0.001); sarcomatoid component (OR 4.11, p < 0.001); tumor size >10cm (OR 2.17, p=0.005); stage pT3-T4 (OR 2.00, p=0.017); and tumor necrosis (OR 1.86, p=0.05). This model was applied to 169 high-risk patients who had two or more of the above risk factors and had lymph node dissection. Thirty-eight percent of these were node positive, of which 44% were not suspected on preoperative imaging. Three key findings of the lymph node mapping were that 44% of metastases skipped the hilum, nodal spread never skipped the authors’ mapped primary landing zone, and that there was a significant proportion of right-side tumors that demonstrated node positivity in the pre-aortic space, indicating a right to left shift.
Finally, Dr. Maranchie pointed out that extent of node dissection does matter: patients with more than 13 nodes dissected had a 32% detection rate vs those with fewer than 13 nodes, who had a 19% detection rate (Terrone et al. BJUI 2002). Whitson and colleagues (J Urol 2011) showed that for pN+ patients, increased lymph node count correlates with a 10% absolute increase in 5-year survival.
She concluded by reporting that extended template node dissection adds little morbidity, patients benefit from node dissection if lymph nodes are involved, that the primary landing zone for nodal spread in kidney cancer is large, clinically positive lymph nodes should be completely resected when feasible, and that extended dissection is recommended for locally advanced RCC regardless of clinical lymph node status.
Presented by:
Jodi K. Maranchie, MD
University of Pittsburgh
Reported by:
Nikhil Waingankar, MD* from the 2014 Winter Meeting of the Society of Urologic Oncology (SUO) "Defining Excellence in Urologic Oncology" - December 3 - 5, 2014 - Bethesda, MD USA
*Fox Chase Cancer Center, Philadelphia, PA USA