Urinary tract cytology: a cytologic-histopathologic correlation with The Paris System, an institutional study.

INTRODUCTION: Urothelial carcinoma (UC) requires lifelong monitoring, commonly through urinary cytology and cystoscopy. Urine cytology has a relatively high sensitivity for detecting high-grade urothelial carcinoma (HGUC); however, its sensitivity for low-grade urothelial neoplasm (LGUN) is significantly lower with wide interobserver variability. The Paris System (TPS) was proposed to create standardized diagnostic categories with defined cytomorphologic criteria. We attempt to evaluate diagnostic efficacy of identifying UC using TPS through cytologic-histologic correlation. MATERIALS AND METHODS: A retrospective search identified 170 cases of urine cytology cases with concurrent biopsies collected during a 2-year time period at University of Rochester Medical Center. Patient age, sex, smoking history, prior malignancy diagnoses, cystoscopy findings, specimen collection method, UroVysion results, and 1-year follow-up of surgical pathology cases were included. RESULTS: Cytologic-histologic correlation was identified in 59% of cases, with 18% true positives and 41% true negatives. Discordant results were identified in 41% of cases; of these, 4% were false positives, 11% false negatives, 12% potential sampling bias, and 14% were low-grade urothelial carcinoma (LGUC). The analysis of this 2-year study finds a positive predictive value of urine cytology for HGUC to be 81%, a negative predictive value of 79%, a sensitivity of 61%, a specificity of 91%, and an accuracy of 79%. CONCLUSIONS: Our results support TPS's ability to improve the reliability and accuracy of interpretations in urine cytology for HGUC. Nevertheless, additional studies are essential to improve the diagnostic accuracy of LGUN, and urine adequacy, in order to improve patient care and early detection, while identifying potential sampling bias.

PD-L1 Assay Concordance in Metastatic Renal Cell Carcinoma and Metastatic Urothelial Carcinoma.

BACKGROUND: Immune checkpoint inhibitors are now standard of care for many patients with metastatic renal cell carcinoma (mRCC) and metastatic urothelial carcinoma (mUC). Given real-world limitations in programmed death-ligand 1 (PD-L1) testing, concordance studies between PD-L1 assays are needed. We undertook comparisons of Dako 28-8 and Ventana SP142 assays in mRCC and Dako 22C3 and Ventana SP263 assays in mUC. PATIENTS AND METHODS: Thirty-two patients with mRCC and 18 patients with mUC who had received immune checkpoint inhibitor therapy were identified. Formalin-fixed paraffin-embedded tumor samples for patients with mRCC were evaluated with Dako 28-8 and Ventana SP142 PD-L1 immunohistochemistry assays. For patients with mUC, formalin-fixed paraffin-embedded tumor samples were evaluated with Dako 22C3 and Ventana SP263 PD-L1 immunohistochemistry assays. RESULTS: The majority (29/32; 91%) of mRCC cases were concordant between assays. The majority (17/18; 94%) of mUC cases were also concordant between assays. CONCLUSIONS: There was strong concordance between PD-L1 assays chosen for comparison in both mRCC and mUC, with similar performance characteristics. One limitation is the small number of cases in this study; larger comparison studies are needed for this biomarker in mRCC and mUC.