Variant histology is associated with more non-urothelial tract recurrence but less intravesical recurrence for upper tract urothelial carcinoma after radical nephroureterectomy.

Abstract

To investigate the prognostic impact of variant histology (VH) on oncological outcomes in patients with upper urinary tract urothelial carcinoma (UTUC) who had undergone radical nephroureterectomy (RNU). A total of 1239 patients with clinically localized UTUC who underwent RNU at a single institution between January 2005 and June 2020 were included. The VH was reviewed by a uro-pathologist at our institution. The Cox regression model was used to perform multivariate analysis, including VH and other established prognostic factors for post-RNU oncological outcomes (intravesical recurrence [IVR], non-urothelial recurrence, and cancer-specific death). Of the 1239 patients with UTUC, 384 patients (31%) were found to have VH. Advanced tumor stage, lymph node metastasis, high tumor grade, lymphovascular invasion, open surgery, and renal pelvis had a significantly larger proportion of UTUC with VH compared to pure UTUC (all p < 0.05). VH was an independent prognostic factor associated with less IVR identified by multivariate analysis, more non-urothelial recurrence, and more cancer-specific mortality. Patients with VH account for 31% with UTUC treated with RNU in this cohort. VH was an independent prognostic factor associated with more non-urothelial recurrence and cancer-specific mortality but less IVR.