Variant histology as a significant predictor of survival after radical nephroureterectomy in patients with upper urinary tract urothelial carcinoma

Objectives To investigate the effect of variant histology (VH) on survival after radical nephroureterectomy in patients with upper urinary tract urothelial carcinoma (UTUC) and the effect of adjuvant chemotherapy on the survival of patients with UTUC with VH. Materials and methods A total of 452 patients who underwent radical nephroureterectomy for UTUC without neoadjuvant chemotherapy in our institution between 1991 and 2012 were retrospectively analyzed. We performed a comparative analysis between pure UTUC and UTUC with VH groups. The Kaplan-Meier method was used to calculate survival estimates for cancer-specific survival (CSS) and overall survival (OS), and log-rank test was used to conduct comparisons between the groups. Univariate and multivariate Cox-proportional hazard regression analyses were performed to evaluate significant variables associated with CSS and OS. Results UTUC with VH was present in 41 (9.1%) patients. UTUC with VH showed aggressive clinicopathological features in comparison with pure UTUC. The Kaplan-Meier curves showed significantly decreased 5-year CSS and OS (both, P<0.001) in UTUC with VH group. Multivariate analysis revealed that VH was an independent predictor of CSS (P<0.001) and OS (P<0.002). The Kaplan-Meier curves also showed significantly decreased 5-year CSS and OS in UTUC with the VH group compared to the pure UTUC group in patients who received adjuvant chemotherapy. Conclusions We found that UTUC with VH harbored aggressive biologic features, and VH was an independent prognostic factor for CSS and OS on both univariate and multivariate analyses. In addition, UTUC with VH group had poorer survival outcomes than pure UTUC group in patients who received adjuvant chemotherapy. Consequently, adjuvant treatment modalities other than adjuvant chemotherapy should be considered in this group.