Urachal Cancer in Germany and the USA: An RKI/SEER Population-Based Comparison Study

Introduction:Urachal cancer (UrC) is a rare but aggressive cancer. Due to its low incidence, structured epidemiological data have only rarely been reported. To date, no valid data on UrC are available for the German population.Methods:Data on incidence and relative 5-year survival of urachal lesions (ICD-10: C67.7) were collected from all population-based cancer registries in Germany, provided by the Robert Koch-Institut (RKI). Data were anonymized and included age, sex, and general histology (ICD-O-3). For comparison, a similar inquiry of the "Surveillance, Epidemiology, and End Results program" (SEER-18) database for the USA was conducted.Results:From 2011 to 2015, a total of 154 and 152 cases of UrC were reported for Germany (RKI) and the USA (SEER-18 area), respectively. Age-standardized incidence was 0.32/1,000,000 age-standardized cases/year in both cohorts, and elderly persons were more often affected. The major histological type was adenocarcinoma (64.9 and 81.6%). Relative 5-year survival was 54.8% (CI: 45.0-64.6) in Germany (RKI) and 64.4% (54.1-72.1) in the USA (SEER-18 cohort).Discusssion/Conclusion:The collected data demonstrate low incidence rates and similar epidemiological and clinicopathological characteristics of UrC for both registries. This is the first report of structured epidemiological data for UrC for the German population.