Evaluation of histological variants of upper tract urothelial carcinoma as prognostic factor after radical nephroureterectomy.

purposeTo evaluate the impact of variant histology on patients with upper tract urothelial carcinoma (UTUC) survival outcomes. MATERIALS AND

methodsA total of 519 patients underwent radical nephroureterectomy without neoadjuvant therapy for UTUC at a single institution between May 2003 and December 2019. Multivariate Cox regression analysis evaluated the impact of variant histology on progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS).

resultsAmong 84 patients (16.2%) with variant histology, the most frequent variant type was squamous cell differentiation (64.3%), followed by glandular differentiation (25.0%) and sarcomatoid variant (2.4%). They showed pathologically advanced T stage (for ≥ T3, 59.5% vs 33.3%, p < 0.001), higher tumor grade (96.4% vs 85.7%, p = 0.025), and higher rates of lymph node metastasis (17.9% vs 7.8%, p = 0.015), angiolymphatic invasion (41.7% vs 25.7%, p = 0.003), tumor necrosis (57.1% vs 29.0%, p < 0.001) and positive surgical margin (13.1% vs 5.7%, p = 0.015). On multivariate Cox regression analyses, variant histology was significantly associated with worse PFS (hazard ratio [HR] 2.23; 95% confidence interval [CI] 1.55-3.21; p < 0.001), CSS (HR 2.67; 95% CI 1.35-5.30; p = 0.005) and OS (HR 2.22; 95% CI 1.27-3.88; p = 0.005). In subgroup analysis, no significant survival gains of adjuvant chemotherapy occurred in patients with variant histology.

conclusionsVariant histology was associated with adverse pathologic features and poor survival outcomes. Our results suggest that patients with variant histology may require a close follow-up schedule and novel adjuvant therapy other than chemotherapy postoperatively.