Royce TJ, et al. - The intent of the authors was to discern the clinical features, therapeutic patterns, and outcomes of patients with nonurothelial cell bladder cancer (NUBC) in the United States. This encompassing clinical characterization and prognosis of NUBC patients unveiled that NUBC patients were presented with considerably different disease characteristics compared to those with UC. They were also presented with more advanced disease, received more treatment, and overall reported inferior outcomes. In order to improve outcomes for such patients, advanced studies were warranted.

Methods

• Researchers selected 163,683 patients with bladder cancer from the National Cancer Data Base during 1998 to 2014.
• Among the candidates, 153,262 had urothelial cell (UC) carcinoma (93.6%) and 10,421 had NUBC (6.4%) further classified as: Squamous cell carcinoma (SC, 2.4%), adenocarcinoma (AC, 1.7%), neuroendocrine (NE, 1.3%), micropapillary (MP, a UC variant histology, 0.3%), lymphoid/haematopoietic (LH, 0.3%), and sarcoma/mesenchymal (SM, 0.3%).
• Analyses were carried out on the entire cohort, those with non-muscle-invasive disease (T0-1, N0, M0), muscle-invasive disease (MIBC, T2-4A, N0, M0), and metastatic disease (T4B or N+ or M+).
• On the basis of histologic subtype, the clinical characteristics and treatment received (surgery, chemotherapy, and radiation) were reported.
• Through the Kaplan-Meier estimates and Cox proportional hazards models, survival analysis was conducted.

Results

• Patients with NE, SC, MP, and AC exhibited a greater tendency of presenting with metastatic disease (11.5% for UC vs. 40%, 31.3%, 17.8%, and 30.6%, respectively, P < 0.001).
• Additionally, those with NUBC illustrated a higher likelihood of having MIBC compared to UC (43% vs. 32.5%, respectively).
• For all patients, those with UC exhibited the possibility of a lesser tendency of undergoing cystectomy, chemotherapy, and radiation therapy (P < 0.001).
• It was determined that NUBC correlated with inferior survival compared to UC (P < 0.001), for all patients.
• The exception was LH, SM, and MP.