The clinical epidemiology of urachal carcinoma: results of a large, population based study.

PURPOSE

Survival data on urachal carcinoma are sparse due to the low prevalence of this cancer. We report urachal carcinoma clinical outcomes and prognostic factors in a large, population based cohort of patients with long-term followup.

MATERIALS AND METHODS

Data were collected from the nationwide Netherlands Cancer Registry. Urachal carcinoma cases were also cross-referenced using the PALGA (Nationwide Network and Registry of Histology and Cytopathology) database. Pathology report summaries were reviewed. A total of 152 patients diagnosed with urachal carcinoma between 1989 and 2009 were included in analysis. The Sheldon staging system was used to classify urachal carcinoma. Median followup was 9.2 years. Primary outcomes were overall and relative survival. Prognostic factors were calculated using univariate and multivariate hazard regression models.

RESULTS

The incidence of urachal carcinoma was 0.2% of all bladder cancers. A total of 45 patients (30%) presented with lymph node or distant metastasis. Five-year overall and relative survival was 45% and 48%, respectively. On multivariate analysis prognostic factors for impaired survival were lymph node metastasis (HR 1.7, 95% CI 1.2-2.6), tumor growth in the abdominal wall, peritoneum and/or adjacent organs (HR 5.2, 95% CI 2.6-10.3), distant metastasis (HR 5.3, 95% CI 2.8-9.9) and macroscopic residual tumor (HR 5.2, 95% CI 1.2-21.8).

CONCLUSIONS

Urachal carcinoma is rare, accounting for 0.2% of all bladder cancers. Many patients present with advanced disease. The prognosis of urachal carcinoma depends mostly on tumor stage, particularly the presence or absence of metastatic disease.