Prognostic Variables in Patients With Non-metastatic Small-cell Neuroendocrine Carcinoma of the Bladder: A Population-Based Study

Abstract

Background: Small-cell carcinoma of the bladder (SCCB) is a rare, highly aggressive, neoplasm. We retrospectively analyzed the Surveillance, Epidemiology, and End Results (SEER) database to investigate the impact of chemotherapy, surgery, and radiotherapy on overall survival (OS) of patients with non-metastatic SCCB.

Materials and methods: The SEER Research Data (2000-2014) were reviewed using the SEER*Stat software. Patients with pure or mixed SCCB, T2-T4, any N, M0, and who received either surgery or radiotherapy with or without chemotherapy (neo-adjuvant, adjuvant, or perioperative treatment) were included. We used the Kaplan-Meier method and log-rank test for estimating survival. Cox proportional hazard regression was used to evaluate the prognostic variables.

Results: A total of 384 cases of SCCB were included in the study (T2, n = 204; T3/4, n = 180), of whom 233 (60.7%) were treated with surgery, whereas 151 (39.3%) received radiotherapy. The median OS was 21.0 months (95% confidence interval [CI], 16.7-25.3 months). Age, race, chemotherapy, type of local treatment, and T and N staging were identified as independent prognostic variables (P < .05). In multivariate analysis, chemotherapy (n = 264) was associated with significant better OS (adjusted hazard ratio [HR], 0.56; 95% CI, 0.42-0.74; P < .000). Patients who underwent surgery showed longer outcome compared with those treated with radiotherapy (adjusted HR, 0.62; 95% CI, 0.47-0.82; P = .001). However, only in the T2 subgroup did surgery (n = 92) retain a significant survival difference compared with radiotherapy (n = 112) (adjusted HR, 0.37; 95% CI, 0.24-0.57; P < .000).

Conclusions: Surgery was associated with better outcome compared with radiotherapy in patients with T2 disease. Chemotherapy was associated with a longer survival in patients with non-metastatic SCCB.

Keywords: Neuroendocrine bladder cancer; Prognostic variables; SCCB; SEER; Small-cell bladder cancer.