Diagnostic value of a comprehensive, urothelial carcinoma-specific next-generation sequencing panel in urine cytology and bladder tumor specimens

Cancer Cytopathol. 2021 Jul;129(7):537-547. doi: 10.1002/cncy.22410. Epub 2021 Feb 4.

Abstract

Background: Urine cytology can reliably diagnose high-grade urothelial carcinoma (HGUC) but not low-grade urothelial carcinoma (LGUC), and a more sensitive test is needed. Previously, a pilot study highlighted the possible diagnostic utility of next-generation sequencing (NGS) in identifying both LGUC and HGUC in urine cytology specimens.

Methods: Twenty-eight urine ThinPrep cytology specimens and preceding or subsequent bladder tumor biopsy/resection specimens obtained within 3 months were included in the study (LGUC, n = 15; HGUC, n = 13). A customized, bladder-specific NGS panel was performed; it covered 69 frequently mutated or altered genes in urothelial carcinoma (UC) that were reported by The Cancer Genome Atlas and the Catalogue of Somatic Mutations in Cancer.

Results: The sequencing results were compared between the urine cytology specimens and the corresponding bladder tumor biopsies/resections. TP53 was the most frequently identified mutation in HGUC cases (11 of 13 [85%]). PIK3CA and KDM6A were the most frequently identified mutations in LGUC: they occurred in 7 of 15 cases (47%) and in 6 of 15 cases (40%), respectively. Additional frequent mutations identified in the panel included ARID1A (n = 5), EP300 (n = 4), LRP1B (n = 3), ERBB2 (n = 2), STAG2 (n = 2), FGFR3 (n = 3), MLL (n = 2), MLL3 (n = 2), CREBBP1 (n = 1), RB1 (n = 1), and FAT4 (n = 1). Overall, the concordance between the cytology and surgical specimens was 75%. The sensitivity and specificity for identifying mutations in urine cytology specimens were 84% and 100%, respectively.

Conclusions: A bladder-specific NGS panel increases the sensitivity and specificity of urine cytology's diagnostic utility in both low- and high-grade tumors and may serve as a noninvasive surveillance method in the follow-up of patients with UC harboring known mutations.

Keywords: cytology; diagnosis; mutation; next-generation sequencing; urine; urothelial carcinoma.

MeSH terms

  • Aged
  • Carcinoma, Transitional Cell / diagnosis*
  • Carcinoma, Transitional Cell / genetics*
  • Carcinoma, Transitional Cell / pathology
  • Female
  • High-Throughput Nucleotide Sequencing*
  • Humans
  • Male
  • Urinary Bladder / pathology*
  • Urinary Bladder Neoplasms / diagnosis*
  • Urinary Bladder Neoplasms / genetics*
  • Urinary Bladder Neoplasms / pathology
  • Urine / cytology*