Diagnostic Accuracy of Clinical Lymph Node Staging for Upper Tract Urothelial Cancer Patients: A Multicenter, Retrospective, Observational Study.

Purpose: Treatment options for the management of upper tract urothelial cancer are based on accurate staging. However, the performance of conventional cross-sectional imaging for clinical lymph node staging (N-staging) remains poorly investigated. This study aims to evaluate the diagnostic accuracy of conventional cross-sectional imaging for upper tract urothelial cancer N-staging.

Materials And Methods: This study was a multicenter, retrospective, observational study. We included 865 nonmetastatic (M0) upper tract urothelial cancer patients treated with curative intended surgery and lymph node dissection who had been staged with conventional cross-sectional imaging before surgery. We compared clinical (c) and pathological (p) N-staging results to evaluate the concordance of node-positive (N+) and node-negative (N0) disease and calculate cN-staging's diagnostic accuracy.

Results: Conventional cross-sectional imaging categorized 750 patients cN0 and 115 cN+. Lymph node dissection categorized 641 patients pN0 and 224 pN+. The cN-stage was pathologically downstaged in 6.8% of patients, upstaged in 19%, and found concordant in 74%. The sensitivity and specificity of cN-staging were 25% (95% CI 20; 31) and 91% (95% CI 88; 93). Positive and negative likelihood ratios were 2.7 (95% CI 2.0; 3.8) and 0.83 (95% CI 0.76; 0.89). The area under the receiver operating characteristics curve (0.58, 95% CI 0.55; 0.61) revealed low diagnostic accuracy.

Conclusions: Conventional cross-sectional imaging had low sensitivity in detecting upper tract urothelial cancer pN+ disease. However, cN+ increased the likelihood of pN+ by almost threefold. Thus, conventional cross-sectional imaging is a rule-in but not a rule-out test. Lymph node dissection should remain the standard during extirpative upper tract urothelial cancer surgery to obtain accurate N-staging. cN+ could be a strong argument for early systemic treatment.