Primary urethral carcinoma: A Surveillance, Epidemiology, and End Results data analysis identifying predictors of...

Primary urethral carcinoma (PUC) is rare, accounting for <1% of genitourinary malignancies. Current knowledge regarding is founded upon tertiary care centers reporting their experiences. We aim to identify factors predictive of outcomes using a nationwide registry database.

The Surveillance, Epidemiology, and End Results-18 registries database was queried for cases of PUC ranging between 2004 and 2010. To identify PUC cases, ICD-O site code C68.0 was used as a filter, hence identifying PUC with histologic subtypes including urothelial carcinoma (UC), squamous cell carcinoma (SCC), and adenocarcinoma (AC). Tumor characteristics were compared using log-rank analysis, and survival outcomes were compared using Cox proportional hazards models.

A total of 419 PUC cases were identified, 250 (59.7%) male and 169 (40.3%) female patients. The most common histology in men was UC (134, 53.6%), followed by SCC (87, 34.8%) and AC (29, 11.6%). The most common histology in women was AC (79, 46.7%), followed by SCC (43, 25.4%) and UC (42, 24.9%). Log-rank analysis illustrated significant difference in cancer-specific survival (CSS) for T-stage, N-stage, M-stage, and stage of PUC with all histological variants combined (P < 0.001). Multivariate Cox proportional hazards model demonstrated that stage and age were significant for survival, with a risk ratio of 1.033 (95% confidence interval [CI], 1.020-1.046)/year of increased age (P < 0.001) and 3.71 (95% CI, 2.72-5.05) for patients with regional or distant spread.

Knowledge of patient and tumor characteristics that influences survival is paramount in dictating management. The present study illustrates that age and stage are factors significantly associated with CSS in PUC.