Prognostic value of lymph node yield during nephroureterectomy for upper tract urothelial carcinoma

Introduction Lymph node dissection (LND) performed during radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC) remains controversial and difficult to evaluate. The aim of this study was to investigate whether removal of more lymph nodes during RNU is safe and improves oncologic outcomes. Methods We evaluated 422 patients who underwent RNU with concomitant LND for upper tract urothelial carcinoma between 1976 and 2015, assessing for an association between total nodes removed, recurrence-free survival, and cancer-specific survival using Cox proportional hazards models. We also investigated the relationship between nodal yield and perioperative metrics and intersurgeon variability using linear regression. Results In our cohort of 442 patients, 239 developed recurrences and 94 patients died of disease. Median follow-up among survivors was 3.7 years (interquartile range: 1.2, 7.4). The median nodal yield was 9 (interquartile range: 4, 16). Among patients with node-positive disease (pN1), we observed a significant improvement in recurrence-free survival (hazard ratio = 0.84 per 5 nodes removed, P = 0.039) and a nonsignificant improvement in cancer-specific survival with an increase in the nodal yield (hazard ratio = 0.90 per 5 nodes removed, P = 0.2). There was no evidence of an association between node yield and operative time, estimated blood loss, or 30-day complications on multivariable analysis. There was significant heterogeneity among surgeons regarding the extent of LND (P<0.0001). Conclusions We found that a more extensive node dissection may improve oncologic outcomes in a subset of high-risk patients without significantly increasing operative time or serious complications. Additionally, we identified considerable intersurgeon heterogeneity regarding the extent of LND furthering the notion of surgeon variability as a nonstandardized factor.