Background: Collecting duct carcinoma (CDC) is a rare tumor that is difficult to analyze in a single-institution setting. The Surveillance, Epidemiology, and End Results (SEER) database was used to examine demographics and outcomes of CDC.
Patients and methods: The SEER registry was queried for patients diagnosed with CDC from 1973 to 2004 who also had available demographic, stage, and survival information (n = 98). Stage at presentation as a function of gender and as a function of race were compared using the chi2 test. Relative survival (RS) curves were computed and were compared using the log-rank test; stage-specific relative survival rates were compared across subgroups using the chi2 test. Stage at presentation was not influenced by race (P = .5) or by gender (P = .488).
Results: Three-year relative survival rates for localized, regional, and distant disease were 93%, 45%, and 6%, respectively (P < .001). Three-year RS were 58% and 33% for White and Black patients, respectively (P = .354), and for males and females, RS was 58% and 45%, respectively (P = .475). Furthermore, there were no significant differences in 3-year stage-specific relative survival rates by race (P = .425) or gender (P = .245).
Conclusion: this study is the largest analysis of CDC and the first to explore the influence of demographic factors on outcomes. Within stated limitations, there appear to be no significant differences in patterns of disease presentation or relative survival rates based on race or sex. Further work is needed to improve outcomes, particularly for patients with regional or distant disease at presentation.