Tumor location at trans-urethral resection is predictive of ipsilateral pelvic lymph-nodal metastases in patients undergoing radical cystectomy for bladder cancer.

Objective: To assess whether tumor location at diagnostic TURBT is predictive of ipsilateral nodal involvement in patients who underwent radical cystectomy (RC) with lymph-nodes dissection for bladder cancer (BCa).

Materials and methods: All patients who underwent RC for BCa at a single institution between 2014-2023 were assessed. Tumor location at TURBT was defined as right-sided, median-line, left-sided, and diffused. Distribution in the percentage of ipsilateral positive lymph-nodes and number of ipsilateral positive lymph-nodes between tumor locations were assessed with Kruskal-Wallis tests. Linear regressions were fitted to assess whether left or right location, compared to the remaining locations grouped, was associated to the percentage and number of positive ipsilateral lymph-nodes.

Results: 239 patients were included. The number of ipsilateral positive lymph nodes was superior in right-sided tumors when compared to the rest of the bladder (0, I.Q.R. 0-1 vs. 0, I.Q.R. 0-0, P = 0.047), as well as the percentage of ipsilateral positive lymph-nodes (0, I.Q.R. 0-14.3 vs. 0, I.Q.R. 0-3.7, P = 0.042). The number of ipsilateral positive lymph-nodes in left-sided tumors was superior when compared to the rest of the bladder (0, I.Q.R. 0-1 vs. 0, I.Q.R. 0-0, P = 0.02), as well as the percentage (0, I.Q.R. 0-13.7 vs. 0, I.Q.R. 0-0, P = 0.036). At linear regression analyses, right- and left-sided tumors were associated with an increased percentage of ipsilateral positive lymph-nodes (P = 0,019 and P = 0,003) out of the total ipsilateral lymph-nodes excised.

Conclusions: Lateral wall tumor location at diagnostic TURBT (either right or left side) predicts a higher percentage of ipsilateral positive lymph-nodes s/p RC.