Prognostic impact of non‐urothelial carcinoma of the upper urinary tract: Analysis of hospital‐based cancer registry data in Japan

Objectives To identify the prognosis of patients with non‐urothelial carcinoma of the upper urinary tract and compare it with that of patients with urothelial carcinoma. Methods We used hospital‐based cancer registry data in Japan to extract histologically confirmed non‐urothelial carcinoma and urothelial carcinoma cases of the upper urinary tract diagnosed in 2008–2009. We estimated the 5‐year overall survival by a Kaplan–Meier analysis. The Cox proportional hazards regression analysis was used to evaluate prognostic factors. Results A total of 2567 upper urinary tract cancer patients with confirmed histological subtypes were identified. The most common histology of non‐urothelial carcinoma was squamous cell carcinoma (n = 88, 3.4%) followed by adenocarcinoma (n = 33, 1.3%) and small cell carcinoma (n = 10, 0.4%). The proportion of advanced stage in the squamous cell carcinoma patients was significantly higher than that in the urothelial carcinoma patients (P = 0.003). In stage IV, the proportion of patients who received a combination of surgery + chemotherapy in the urothelial carcinoma group was higher than that in the non‐urothelial carcinoma group (34% vs 16%, respectively). The 5‐year overall survival rates of the non‐urothelial carcinoma patients at stages I–III and stage IV were significantly worse than those of the urothelial carcinoma patients (P = 0.003, P