Future goals of upper tract urothelial carcinoma endoscopic management

Despite advancements in technology, the diagnosis and management of upper tract urothelial carcinoma (UTUC) has remained challenging. On a recent meta-analysis, the cumulative nondiagnostic ureteroscopic biopsy rate was 8%, and unable to perform staging in 32% of patients, with rates as high as 64%.1 However, even when biopsies were successfully performed, the meta-analysis found that understaging occurred in 46% of patients (ranging from 38% to 54%) and undergrading occurred in 29% of patients (ranging from 15% to 44%).1 In a recent review article focusing on the future of UTUC endoscopic management, the authors mention crush artifact limiting pathologic evaluation on biopsy, as well as the discordance between biopsy pathology and final pathology on nephroureterectomy specimen.2 The authors also suggest that the primary goal of ureteroscopic biopsy should be identification of histologic type and grade, rather than stage, due to difficulty sampling the tumor base.2 Unfortunately, this mentality will maintain current limitations and shortcomings, rather than address the high rates of UTUC understaging and undergrading that fundamentally plague its management. Clinical staging in UTUC may be improved with imaging that can assess subepithelial connective tissue invasion. Vesical Imaging Reporting and Data System (VI-RADS) is increasingly utilized to preoperatively stage bladder tumors. In a recent study that performed multiparametric magnetic resonance imaging (mp-MRI) before radical cystectomy (RC), VI-RADS score was found to be useful in predicting muscle invasion and perivesical fat infiltration on RC specimen. Although less explored, mp-MRI has been evaluated in the upper tract setting with promising early results. A study compared patients who underwent both computed tomographic urography (CTU) and diffusion-weighted MRI (DW-MRI) with pathology specimens, the majority being nephroureterectomy specimen.3 Although DW-MRI sensitivity was numerically less than CTU (92 vs. 98%, p = 0.25), DW-MRI specificity was numerically greater than CTU (91% vs. 78%, p = 0.065).3 While mp-MRI may not currently be widely utilized in the management of urothelial carcinoma, this technology is showing promising results in both bladder and upper tract tumors. In addition to advancements in preoperative imaging to improve clinical staging, endoscopic surgical techniques should also be developed to enhance both diagnostic and therapeutic capabilities in UTUC. Endoscopic urologic techniques have progressed toward en bloc enucleation of bladder tumors and prostate adenomas, making enucleation of upper tract tumors a natural extension. A recent surgical technique demonstrates en bloc enucleation of an upper tract tumor to safely achieve extensive histopathologic information and complete tumor resection.4 In this manuscript, the authors detailed a ureteroscopic laser enucleation of a 2-cm renal pelvis tumor to identify low-grade histology and extensive subepithelial connective tissue along the tumor base. The authors enter the subepithelial connective tissue plane with low ablation laser settings and maintain this plane through laminar irrigation from the ureteroscope.4 This technique highlights the ability to perform an endoscopic resection of an upper tract tumor to obtain a large caliber tissue biopsy using a basic ureteroscope and laser that are available to most urologists. While undergrading is likely to improve with larger caliber biopsies, understaging is unlikely to improve unless endoscopic surgical techniques fundamentally change. The authors have no acknowledgments to include. Joshua S. Jue, M.D., Mahmoud Alameddine, M.D., and Noel A. Armenakas, M.D., were all responsible for the drafting and critical revision of this manuscript. The authors have no financial disclosures to include. None.