Impact of Variant Histology on Clinical and Pathological Outcomes in Patients with the Upper Urinary Tract Urothelial Carcinoma

Objectives: The objective of the study was to determine the effect of variant histology on pathological outcomes and survival in patients operated for the upper urinary tract urothelial carcinoma (UTUC).Methods: Data of 128 patients who were operated for UTUC between 2001 and 2019 were retrospectively analyzed. Patients with pure urothelial carcinoma and patients with variant histology were compared in terms of demographics, pathological outcomes, and survival.Results: The mean age of the patients was 65 +/- 11 years, female to male ratio was 30/98 and median follow-up period was 26.5 (1176) months. Variant histology was detected in 14.8% of patients. Variant histology was found to be associated with surgical margin positivity, lymph node metastasis, presence of lymphovascular invasion, high tumor stage and grade (p=0.001, p=0.012, p=0.001, p=0.002, and p=0.009, respectively). Three-year cancer-specific and overall survival rates were 79.6% and 77.3%, respectively. There was no statistically significant relationship between variant histology with cancer-specific and overall survival (p=0.514 and p=0.515, respectively).Conclusion: Variant histology of UTUC was found to be associated with locally advanced disease, but its effect on survival could not be demonstrated.