Presentation Authors: Willem Xu*, Saum Ghodoussipour, Gus Miranda, Jie Cai, Anne Schuckman, Siamak Daneshmand, Hooman Djaladat, Los Angeles, CA
Introduction: Upper tract urothelial carcinoma with variant histology (UTUC-VH) has been understudied and its prognostic implication is unknown. We evaluated perioperative and oncologic outcome of patients with UTUC-VH and compared them to pure urothelial carcinoma (PUC) following radical nephroureterectomy (RNU), with the majority of patients undergoing lymph node dissection (LND).
Methods: Using our IRB approved, prospectively maintained UTUC database, we identified all patients undergoing RNU with intent to cure. Tumors were divided into PUC or VH based on pathologic evaluation at resection. Using Fisher's Exact Test, we compared PUC and VH with primary outcomes of recurrence free survival (RFS) and overall survival (OS). We also examined perioperative outcomes, including 90-day complication and readmission rates.
Results: Of 160 patients undergoing RNU from 2009-2018, 139 patients had PUC (87%), and 21 had VH (13%). The most common histologic variant was squamous (81%), followed by sarcomatoid (14%) and small cell/neuroendocrine (5%). Patients with VH presented with poorer ECOG status (0.71 vs. 0.59, p=0.0383). On final pathology, patients with VH had a higher incidence of non-organ confined disease (â‰¥pT3) (71.4% vs. 37.2%, p=0.0041), but similar pN+ (16.5% PUC vs. 14.29% VH, p=1.00). Neoadjuvant (9.52% for VH vs 10.79% for PUC, p=1.00) and adjuvant chemotherapy (28.57% for VH vs 15.11% for PUC, p=0.129) were used similarly between both groups. 90-day complications (38.1% VH vs 25.9% PUC, p=0.295) and readmission rates (14.29% VH vs 6.47% PUC, p=0.196) were comparable between groups. On univariate Cox regression, VH was associated with decreased OS (HR 3.07, 95% CI 1.11-8.49, p=0.03). There was no association between VH and RFS (HR 1.60, 95% CI 0.72-3.55, p=0.24). On multivariable regression, VH failed to reach significance for RFS/OS (HR 1.12, 95% CI 0.49-2.56, p=0.79; HR 2.29, 95% CI 0.80-6.58, p=0.12).
Conclusions: Patients with variant histology of upper tract urothelial carcinoma present with higher pathological stage. Larger and multi-institutional studies are needed to confirm these findings as well as their effect on oncologic outcome.