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 < 0.001, respectively). In multivariate analyses, age >= 73 years, advanced stage (stage IV), tumor location (ureter) and the presence of non-urothelial carcinoma histology were independent poor prognosis factors. Conclusion The prognosis of non-urothelial carcinoma patients is worse than that of urothelial carcinoma patients, especially for non-urothelial carcinoma patients at stage IV. More effective systemic therapies are required to improve these patients' oncological outcomes.