Clinicopathological features and their impacts on the prognoses of patients with nonurothelial carcinoma: A hospital-based cancer registry in Japan.

Abstract

555 Background: Urothelial carcinoma (UC) is the most common histology of genitourinary (GU) tract cancer. Non-UC tumors in the GU tract appear to be more aggressive than UC at that location, but the clinicopathological features and their impacts on the prognoses of the non-UC patients are not known due to the low numbers of these patients. Methods: We used Hospital-Based Cancer Registry (HBCR) data in Japan to extract non-UC cases, i.e., patients with adenocarcinoma (AC), squamous cell carcinoma (SCC), or small cell carcinoma (SmCC) of the GU tract who were diagnosed in 2008–2009 with histological confirmation and had received first course of treatment. We retrospectively analyzed the clinicopathological features of these patients, stratified by the bladder and the upper urinary tract (UUT) as tumor locations. We used a Cox proportional hazards regression to identify prognostic factors associated with the overall survival (OS). Results: Of the 8,095 cases at the bladder and 2,580 cases at the UUT, 384 (4.7%) and 131 (5.1%) non-UC cases were identified, respectively. The proportions of histologic subtypes in the bladder were 1.7% AC, 2.4% SCC, and 0.7% SmCC. In the UUT group, these proportions were 1.3%, 3.4%, and 0.4%, respectively. At both tumor locations, the distribution of ages was similar across all subtypes, with the age peak in the 70s. More patients with non-UC were diagnosed at an advanced clinical stage compared to the patients with UC at either location. The 5-yr OS rates of the non-UC patients with a tumor in the bladder and at the UUT were 40% and 26%, whereas the corresponding 5-yr OS rates among the UC patients were 61% and 52%, respectively. A multivariate analysis revealed that the presence of non-UC was significantly associated with increased mortality (hazard ratio 1.66, 95% confidence interval 1.48–1.87) regardless of the tumor location. Conclusions: The clinicopathological features of the non-UC patients were similar between both tumor locations. The presence of non-UC was associated with poor prognosis regardless of the tumor location. A standard of care must be established for non-UC patients, since the prognoses of these patients are not satisfactory.