Low-grade ureteroscopic biopsies frequently undergraded upper tract urothelial carcinoma in surgical cohort

Accurate grading of upper tract urothelial carcinoma is important when considering kidney-sparing treatment rather than radical nephroureterectomy. Researchers retrospectively reviewed 913 patients who underwent nephroureterectomy at a tertiary center between January 2008 and December 2024. The primary endpoint was agreement between ureteroscopic biopsy grade and final surgical pathology; 125 patients had both grades available for analysis.

Overall concordance was 82.4% (103/125), with moderate agreement by Cohen’s kappa (0.423). Among 29 low-grade biopsies, 17 (58.6%) were upgraded to high-grade disease after surgery. Positive predictive values were 41.4% for low-grade and 94.8% for high-grade biopsy findings. Reported multivariable associations with undergrading included age younger than 65 years (OR 2.66), renal pelvis location (OR 2.59), and multifocal disease (OR 2.12).

The findings support caution in relying on low-grade biopsy results alone to select patients for kidney-sparing ablation. However, the retrospective, single-center analysis included only patients who ultimately underwent nephroureterectomy, limiting generalizability to all potential kidney-sparing candidates. Ureteroscopy and biopsy were selected at surgeon discretion. The supplied text also reports inconsistent biopsy-group totals—164 in the abstract versus 163 in the methods—which warrant clarification.