(UroToday.com) The 2024 Southeastern Section of the AUA (SESAUA) annual meeting featured a bladder cancer session and a presentation by Dr. Saad Sabbagh discussing a national analysis evaluating the role of lymph node dissection in patients with high-risk upper tract urothelial carcinoma.
Lymph node dissection is recommended for high-risk upper tract patients for its staging benefit and potential oncologic benefit. However, its impact on overall survival remains uncertain, specifically in patients with no suspicion of nodal involvement on clinical imaging. Although it represents less than 10% of urothelial carcinoma cases, patients with lymph node involvement have a poor prognosis, with a 5-year survival of only 39%. The aim of this study presented at SESAUA was to evaluate the role and quality of lymph node dissection in overall survival among patients with stage cT2-4N0M0 disease and to explore the association of varying extents of lymph node dissection with overall survival.
Dr. Sabbagh and colleagues queried the National Cancer Database from 2004 to 2020 to identify 8,543 patients with cT2-4N0M0 upper tract urothelial carcinoma who underwent nephroureterectomy (n = 6,614). After excluding unknown values for the variables of lymph node dissection, chemotherapy, and radiation, 4,191 patients were included in the analysis. Patients were divided into two cohorts based on the performance of lymph node dissection. The propensity score matched sample, based on clinical covariates, was constructed with greedy nearest neighbor matching on the logit of the propensity score using a caliper of width equal to 0.2 of the standard deviation of the logit of the propensity score:
The Cox proportional hazards model with robust variance estimators and a Kaplan-Meier curve was performed to compare the survivorships between the propensity score paired samples.
The median age at diagnosis was 73 years (IQR 66-80), patients mostly had cT3 stage disease (52.1%) and high-grade disease (51.5%), the most common site of primary tumor was in the renal pelvis (61.7%), and perioperative systemic chemotherapy was administered in 22.6% of the cohort. Among the lymph node dissection group, 50.2% had 1-3 lymph nodes dissected:
The Cox proportional hazards model revealed that overall survival for the no-lymph node dissection group and the lymph node dissection group (median overall survival 47.0 months and 46.0 months, respectively) were not significantly different (HR 0.97, 95% CI [0.86-1.08], p = 0.6334). In the propensity score-matched samples, upon stratifying the patients in the lymph node dissection group according to the number of lymph nodes dissected, there was no significant difference in overall survival between the no-lymph node dissection group and an increasing number of lymph nodes dissected:
With regards to prognostic clinical factors, older age, higher cT stage, high-grade disease, and lymphovascular invasion were all associated with worse overall survival. Additionally, perioperative systemic chemotherapy administration was associated with an improved survival of 20%:
The retrospective nature and the heterogeneity of cases identified in the NCDB limits the ability to account for non-observable confounding factors. Additionally, there is no ability to identify the template or anatomic region for the lymph node dissection, the length of hospital stay is not documents, and no other survival parameters can be assessed. The strengths of the study include the large sample size in the NCDB, using a propensity-score matched analysis, and the data in the NCDB reflecting real world outcomes.
Dr. Sabbagh concluded his presentation discussing a national analysis evaluating the role of lymph node dissection in patients with high-risk upper tract urothelial carcinoma with the following summary statements:
- Lymph node dissection was not associated with improved overall survival after propensity score-matched analysis
- While lymph node count could improve staging, it was not associated with improved overall survival
- Perioperative systemic chemotherapy, unlike lymph node dissection and radiation, correlated with improved overall survival
Presented by: Saad Sabbagh, MD, Cleveland Clinic Florida, Weston, FL
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Associate Professor of Urology, Georgia Cancer Center, Wellstar MCG Health, @zklaassen_md on Twitter during the 2024 Southeastern Section of the American Urological Association (SESAUA) Annual Meeting, Austin, TX, Wed, Mar 20 – Sat, Mar 23, 2024.