MP40-03: The added value of systematic biopsies in the diagnosis and characterization of upper tract urothelial cancer

Andrea Gallioli, Pietro Diana*, Angelo Territo, Josep Maria Gaya, Alberto Piana, Pavel Gavrilov, Francesco Sanguedolce, Julio Francisco Calderón, Antoni Sánchez-Puy, Joan Palou, Alberto Breda, Barcelona, Spain

Introduction: The standard procedure for the diagnosis of upper tract urothelial tumor (UTUC) may be suboptimal in providing a histological diagnosis, thus, affecting disease management. The employment of ureteral systematic biopsies (USB) has never been considered in addition to the current standard endoscopic technique. We aim to investigate the added value of USB in the diagnosis and characterization of UTUC.

Methods: This is a retrospective study analyzing patients from 01/2017 to 12/2020 with suspicion for UTUC that underwent both USB and selective cytology (SC) as part of the institutional diagnostic work-up. USB consisted in performing at least 2 biopsies in each ureteral portion (proximal, medium, distal, and pelvis) during diagnostic ureteroscopy (URS). Cohen’s Kappa was used for agreement analysis. This study was approved by the institutional ethical committee (2014/17).

Results: We analyzed 44 patients and 54 renal units. 24/54 (44.4%) and 30/54 (55.6%) patients presented with a positive and a negative URS, respectively. 27/54 (50%) patients were diagnosed for UTUC with standard endoscopic diagnosis (URS + SC +/- lesion biopsy). With the addition of USB to the procedure 32/54 (59.3%) patients had a positive cytohistological analysis showing a percentage increase in overall diagnosis of 18.5%. In case of negative URS (30 cases), 2 (6.7%) patients had positive SC only, 5 (16.7%) had both positive SC and USB, and 5 (16.7%) patients had USB positive only. The concordance between USB and SC result was moderate (K = 0.43). USB brought a percentage increase in diagnosis of this population of 71%. In case of positive URS, 14/24 (58.3%) lesion biopsies, 13/24 (54.1%) SC and 13/24 (54.1%) USB were positive. Out of 10 negative lesion biopsies, 6 (60%) patients had a positive SC. Lesion biopsy histology resulted low-grade in 10/14 (71.4%), high-grade in 3/14 (21.4%) and CIS in 1/14 (7.1%). USB resulted positive in 9/14 (62.3%) of those who had positive lesion biopsies. Among patients with low-grade lesion biopsy, USB showed multifocal low-grade disease in 5/10 (50%) cases and CIS in 1/10 (10%) cases. 2/3 patients with high-grade disease at lesion biopsy showed multifocal UTUC at USB. USB and lesion biopsy were concordant in the diagnosis of the only case with CIS.

Conclusions: The endoscopic diagnosis of UTUC should rely on lesion biopsy, SC and USB. In negative URS, USB may significantly increase the diagnostic rate of UTUC. In positive URS, SC may help providing a pathological diagnosis in negative biopsies. On the other hand, USB helps the characterization of the disease and, thus, may potentially influence its management.

Source of Funding: none